I was following the constable's directions toward Islington when a two-wheeled carriage cut out of the thick traffic and jolted to a halt by the kerb. The driver, a dull-eyed man with an oddly shaped head much too small for his body, stared slackly ahead, taking no notice of the spirited oaths of a carter who had been forced to rein in his horse to avoid a smash. The carriage door sprang open and the passenger leaned forward like a half-opened jack-knife and beckoned to me—it was the white-haired man from the seance, Dr. Pretorius.

I was young then, and much less cautious than I am now, and I accepted Dr. Pretorius's invitation with the same confident curiosity which had spurred me to attend the seance. Dr. Pretorius pulled sharply on a chain as soon as I had climbed inside the carriage, and it moved off with a sharp jerk that banged the door shut and threw me onto the narrow leather-covered bench facing him.

"I am delighted to meet you at last, Mr. Carlyle," he said. His accent was cultivated; his tone both mocking and amused. He wore the same black coat and high-collared shirt as at the seance, and a soft, shapeless hat perched on his vigorous mop of white hair. When I asked where we were going, he said, "You have not been long in the city, I believe. Allow me to show you something which will be of great interest to a man such as yourself. It's just a little way beyond what was the valley of the Fleet, within the old wall."

"I am flattered that you take an interest in me," I said, and it was not entirely untrue. At that moment, I was not afraid of this devilish man; I was eager to learn more of him, and to discover just what he knew of the matter of the dead. That he knew something, I did not doubt at all.

"It wasn't hard to track you down," he said. "Men like us are rare enough, and growing rarer, but we have a natural affinity."

"I must assume that the thing in the cellar was yours."

Dr. Pretorius's smile was both cunning and mischievous. "Very remarkable, wasn't it? I created it directly from seed by principles I discovered many years ago, in another country. I had dreams of populating the world with a new race of creatures made entirely by men, but they were frustrated by the failure of a pupil I thought better than he was. Mrs. Shelley wrote a popular romance which burlesques his downfall—perhaps you have read the revised edition that was recently reprinted? No? Well, no matter. It omitted my contribution to the affair completely, and had altogether too much sensation and not enough science. And besides, that was the past, and now we are at the dawn of a new age, and I have new plans: very powerful plans.

"Tell me," he said, leaning close, "did you have any luck, in that horrible cellar?"

I felt a first pang of alarm, and was horribly aware of the fingerbones I had recovered. They seemed to beat like a tell-tale heart in the breast pocket of my jacket, and I had to quash the impulse to put my hand over it, to hide my discovery from Dr. Pretorius's piercing scrutiny. Suppose he had set several imps to keep watch in the cellar, and I had seen only one? Suppose one of the urchins peeking at the window had been in his employ?

I said, as casually as I could manage, "Is the murder of particular interest to you, Dr. Pretorius, or are you merely interested in it for the sake of sensation?"

He was not at all put out by this, but sat back, saying, "Very good, very good," as he pulled a flask from his jacket. He drank, shuddered as delicately as a cat, and offered it to me, explaining, "A little gin, to celebrate our meeting. It's my only weakness."

I declined, and he shrugged. "Were you searching that cellar out of 'interest in sensation,' or could it be that you are in the employ of your new friend?"

"If I have business with him, that's my business, and his."

"Not if it interferes with the business of others," Dr. Pretorius said, with sudden sharpness. But then he smiled, and said, "But we should not be arguing, my dear Mr. Carlyle! We are both interested in the same truths. We know things about the world that other men dare only dream about. We know how the world really works—the truth that underlies the petty reality which men like your engineer friend labour to master. They are like ants, building castles from crumbs of sand: mighty fortress to them, but to us mere heaps we can crush in an instant. Yes, I saw how that young man took you up, Mr. Carlyle, and I wish I had spoken to you then, but I confess that I was enjoying the scene you created, and was too slow to follow its creator. A very amusing diversion it was, too, far better than the silly bit of cheap theatre those gypsies put on. That, I must say, was very disappointing, but meeting you is more than enough compensation."

"You know something of the matter of the dead?"

"I know much about the matter of life, my friend. More, dare I say, than your poor parents. Oh yes, I know about their experiments into the nature of the human soul, the ghastly business with the resurrection men, and the unfortunate accident that occurred when they tried to reanimate the dead with ghosts.

"I hope you don't mind me mentioning it," he added, with sly false sweetness. "By the band that you wear, I see that you are still in mourning."

"As a matter of fact, doctor, I mind very much. It really is none of your business."

"Oh, but I think it is," Dr. Pretorius said, tapping the side of his nose with a finger. "I mentioned a pupil of mine. He was in the resurrection trade too. He stitched new bodies from old, and infused them with electricity in place of the life force. Not so much different from your parents' work, I think, and it came to an equally bad end. It was almost the death of me, in fact, but I escaped, and learned some valuable lessons, too. Our driver, for instance. Perhaps you noticed him? He has greatly benefitted from my attentions. In his former life he was nothing but a common thief, who thought to break into my establishment one night and steal the day's takings. I caught him, and I made a new man out of him. A little brain surgery, some cranial reconstruction … Ah, here we are."

The carriage jerked to a halt—its driver was all stop or all go, and nothing in between—and Dr. Pretorius opened the door and sprang out with surprising alacrity. He took my arm when I climbed out after him, and steered me across the pavement to a iron grill set in the base of the wall of a bank.

"The London Stone," Dr. Pretorius said grandly. "I can see that you are unimpressed, but I think that if you look closely, you'll understand why I brought you here."

It sat in a niche behind the grill, a blackened, lump of stone about two feet across, quite undistinguished except for the pair of grooves worn in its rounded top. If it had been lying on a piece of waste ground, I would not have troubled it with a second glance, but as I stared at it I felt as if it was opening up like the mouth of a well or shaft that plumbed a dimension I had never before noticed. When Dr. Pretorius pulled me away, the ordinary noise and bustle of the street reasserted itself with the suddenness of an explosion, leaving me so faint that I reeled back against the wall.

"You see its puissance," Dr. Pretorius said, like a teacher encouraging his best pupil. "I knew you would."

I could still feel its black power in a corner of my mind, like the onset of a headache, or a thunderstorm. I said, the words coming so hard they might have been the first I spoke after a year of silence, "What is it?"

"Some say that it is a Roman milestone, perhaps the pivot from which all measurements in the province of Britannia were taken. Others claim that it came from Troy, brought here by the great-grandson of Aeneas, who led the exodus of the defeated Trojans after the Greeks destroyed their city; they would have it that London is the New Troy."

Dr. Pretorius struck an attitude and declaimed with actorly vibrato, "'And Kings be born of thee, whose dredded might shall aw the World, and Conquer Nations bold,'" then winked at me, and added, "Or perhaps it is no more than a bit of rubble from some forgotten building of old Roman London. It does not really matter what it was. What matters is what men think it is, as I'm sure you'll agree. The Kentish rebel, Jack Cade, rode into the City and declared himself mayor by striking the stone with his sword. Many others have sworn similar oaths upon it."

"Why have you brought me here?"

"This stone is on public display, on a public street. Do you not think, in a city as ancient as this, where the streets are raised a good twenty feet above the original ground by the rubble and trash of the ages, that there might be other stones, more puissant, more powerful, hidden away beneath our feet?"

"If there are such stones, Doctor, I believe that they should stay buried. I certainly understand why this one is caged—not to protect it from the public, but because, like a wild beast, the public must be protected from it."

"I'm disappointed," Dr. Pretorius said, although he was still smiling his sly, feline smile. "I thought you a man of ambition and vision, like myself. Perhaps it is the shock. Perhaps," he said, offering his flask, "a little gin will help you think more clearly."

"I can think clearly enough," I said. I was angry, stung by Dr. Pretorius's insinuations about my parents, and my anger made me very reckless. "I think that Coffee Joe was murdered because he had found something you need. I think you flatter me because poor Coffee Joe resisted your questioning, and now you need my help to find what you seek."

"I do not need your help to look for what I already have," Dr. Pretorius said, and wagged a bony finger in my face when I started to speak. "We are equals, my dear Mr. Carlyle, and we should not conceal anything from each other. The engineer has hired you, I suppose, to rid that ridiculous tunnel of a malign influence. Yes, I know that you went there with him last night. He heard of the murder, realised that the man's boasts of finding something were true, swallowed his considerable pride, and attended the seance. He hoped to ask a question of a ghost, and found you instead. And what, I wonder, have you found?"

"I won't help you."

"I could take it from you. I could freeze your blood with one word and take it now." Dr. Pretorius studied me for a moment, then said, "The engineer does not know what he has stumbled upon. It is a far greater matter than removing a hex from a hole in the ground."

"Nevertheless, he is my client."

Dr. Pretorius laughed. "You are a stubborn fellow, Carlyle, but not too stubborn, I hope, because I would not like to lose a talent like yours. Such wonders we could do together! When you are ready to talk with me, I can be found at the Museum of Natural Curiosities, on Farringdon Street. It is not far from here—just outside the old walls. Now, you will have to excuse me. Things are progressing very well, and I must be about my business."

As soon as Dr. Pretorius had climbed into his carriage, the horse bolted as if stung by a bee. Dr. Pretorius waved from the window, and the carriage and its strange cargo was swallowed in the unending stream of traffic.

The Museum of Natural Curiosities was a double shop-front, its woodwork painted bright red and the glass of its windows gilded. Boards listed the wonders to be seen within (amongst others, a dog-headed boy, a two-headed sheep, the skeleton of a giant, a genuine mermaid from the Floridean shore, an exquisite miniature ballerina). A large black man stood in the doorway, his muscular arms crossed over the keg of his chest as he scrutinised every passerby. He wore a kind of Arabian Nights costume of loose, buttercup yellow trousers, a broad cloth belt, a deeply slashed pink tunic, and a white turban. The sword sheathed in his belt seemed to be no more than painted wood, but he was of such a size that he would have needed no other weapon than his fists to deal with most troublemakers. I had no doubt that he was the man who had murdered poor Coffee Joe.

I watched the museum and its muscular guardian from the other side of the busy road, munching on roast hazelnuts purchased from a street vendor, but saw no sign of Dr. Pretorius. At last, I took my chance and crossed the road when the heavy traffic came to a standstill (all around me, hundreds of horses, momentarily released from their work, snorted and tossed their heads), coolly walked past the Museum and its forbidding guard, and entered the tobacconist's next door. For the price of a screw of snuff, I learned that the Museum had been open for just six months, and that the tobacconist, who lived above his shop, was thinking of bringing legal action against the owner because of the construction work that continued day and night, and which more than once had caused his cellars to flood.

After escaping from the tobacconist's torrent of complaint, I walked north through the brawling streets toward my lodgings, pausing only to donate my screw of snuff to an indigent on a street corner, with the request that he stop torturing his set of bagpipes until I was out of earshot.

I took supper with Mrs. Rolt and Mr. Rolt and their two daughters, and retired to my room as soon as I could decently disengage myself from the general round of conversation. The encounter with Dr. Pretorius had exhausted me, and I was eager to examine the grisly remnant which had cost Coffee Joe his life. Yet although I studied them long and hard, I could find no power, not so much an imp, in the conjoined stubs of blackened bone, and I could not imagine why Dr. Pretorius needed them, and what they might signify in the matter of the tunnel.

At last, I wrapped the bones in a clean linen handkerchief, set them on the little table that served as my desk, and made a few notes about my adventures of that day before retiring.

I was lacing up my boots when I noticed that the handkerchief had somehow become unwrapped, and that the two fingerbones had fallen to the floor, lying there in their scraps of black skin like the mummy of an exotic caterpillar.

When we met in the yard, I told Brunel of my discovery of the fingerbones, the encounter with Dr. Pretorius, and the dream. He listened with close attention, absorbing the matter of the interrogation of Coffee Joe's ghost as if it had been a description of some clever bit of lathe work, and asked at the end if he could inspect my prize. I had interred the bones in a tin which had lately contained parma violet pastilles. Brunel stirred them with his forefinger, and said, "You think that this gave you your nightmare of drowning?"

"Not of drowning, Mr. Brunel; of being drowned. Of being sunk deep in cold, lightless water, with water filling my nose and mouth and lungs, and such a great weight of water pressing down on me so that I could not move."

"My dreams were of being drowned when the tunnel flooded, instead of escaping," Brunel said, looking sideways at me. An unlit cigar was stuck in his mouth. "Still, it's not so very different. But if your dream was given to you by these little bones, what gave me mine?"

"In my limited experience of bones, Mr. Brunel, where you find one, you are likely to find others to match."

Brunel grinned around his cigar and handed the tin back to me. "You think that these little bones came from a body lodged above the tunnel. Well, it's time to look for it, don't you think?"

"You promised 'an unusual perambulation.' What, precisely—"

"Let's not spoil the surprise," Brunel said, and took me by the arm and steered me across the yard.

It was a fine sunny day, and the masts of the ships anchored along the edge of the river were like so many black trees scratching the blue sky above the roofs of the warehouses, as if Birnam Wood had waded into the river to pause and cool its rooty feet before resuming its march on Dunsinane. A wharf stood up to its knees in the low tide. A small boat with some kind of cargo draped in oiled canvas was moored on one side; an ordinary skiff with a man waiting at the oars on the other. As soon as Brunel and I had settled into the skiff, the boatman cast off and with strong strokes hauled us aslant the river's strong race, each dip of the oarblades releasing little packets of noxious stink that blew past us in the hot, heavy breeze. Brunel lit his cigar against the smell; I covered my mouth and nose with the handkerchief which had lately acted as a winding sheet. The bristling hedge of ships along the far bank, and the roofs and steeples rising beyond them, were shrouded in a thickening haze. A steam packet went by, dragging a thick tail of smoke behind it, its paddlewheel threshing up foamy waves that rocked and rerocked our little skiff as they chased each other toward the bank. Brunel grinned when I clutched at the damp wood of my seat, and pointed to a low dark barge anchored a little way off. There was a crane angled up from its midsection, and on the deck below the crane's beak, connected to it by a cradle of slack chains, was a bronze sphere that, with sharp highlights winking from it in the hot sunlight, could have been a bell taken from a cathedral tower. "There's our destination," he said.

"The barge is moored over the end of the tunnel, I take it."

"Not at all. The tunnel extends more than fifty feet beyond. But that, so I calculate, is the place it reached when Coffee Joe quit his position. What is it, Mr. Carlyle?"

The bones had begun to rattle inside their little coffin, which I had tucked in the breast pocket of my jacket. I took out the tin and placed it flat on my palm. As Brunel watched it shiver and shake, I said, "If they can produce bad dreams, I suppose we should not be so astonished that they are also able to move."

"I don't doubt that they are moving," Brunel said. "The question is, why are they moving?"

"Perhaps these are animated by a desire to be reunited with their fellows, although I confess that I have never before seen such a thing."

"They are altogether unique, aren't they? With your permission, Mr. Carlyle, I would like to try a little experiment."

He had me pinch the tin between thumb and forefinger as, watched by a couple of men on the low deck, the boatman took us parallel to the barge's black, wet side. The tin began to vibrate urgently and noisily when we cleared the bow, and Brunel told the boatman to let the current take us for a moment. The rattling grew less as we drifted backward; increased again as we rowed forward. Brunel took a sighting of either shore to mark the spot, and told the boatman to make for the ladder.

After we climbed aboard, Brunel introduced me to the captain and then strutted over to the gleaming bell (his reflection swimming up to its shining surface to meet him) and briskly rapped it with his knuckles. "I borrowed it from the West India Dock Company, Mr. Carlyle. Are you much troubled by enclosed spaces, by the by? I clean forgot to ask."

"No more than any other man," I said. "What does a bell have to do with dredging up—"

"Dredging? No, sir, that's far too chancy, as I think someone else has discovered. We're going to dig it up."

Brunel left me to wonder about that as he gave the captain instructions, pointing to the spot of water a few dozen yards off the bow of the barge where the fingerbones had become most agitated. The barge blew a cloud of black smoke from its tall chimney, raised its anchor, and moved against the current and dropped anchor again, all in a minute. Brunel satisfied himself as to the spot, and then two men started up the steam engine of the crane. Chains rattled as they were wound on a great drum, the frame of the barge creaked as the bronze bell was lifted a yard above the deck, and I tardily understood Brunel's audacious plan.

A narrow wooden footboard ran around the inside of the bell, a foot or so above the rim, and there were leather straps rivetted to the curved metal wall. Hatless and in our shirtsleeves, accompanied by a gruff labourer armed with a grappling hook and a wooden shovel, Brunel and I clung to these straps as the bell was swung out over the swiftly-running brown water and lowered into it.

My ears sang and popped as we descended. The level of the circle of water beneath our boots crept toward the footboard, and Brunel explained that the eagerness of the air to escape the bell almost precisely countered the eagerness of the water to enter, but air was compressible while water was not.

"I used this apparatus before," he said, "to inspect the aftereffects of the first inundation. I was able to step from the footboard onto the corner of number twelve frame of the tunnelling shield: a quite remarkable experience. What do the bones say? Are we close?"

The tin was tucked into the pocket of my trousers, and the fingerbones inside it were rattling like a demented castanet. "They are very excited," I said.

The bell grounded with a solid thump. Beneath the rim of the footboard, a circle of black mud and gravel lay under about six inches of cloudy water. Brunel, the labourer and I scoured it with grappling hooks until, red-faced, our eyes starting from their sockets, we were forced to pull the communicating string, and were lifted to the surface and a brief respite in the fresh air before being submerged again.

And so it went for half a dozen attempts, until at last the labourer hooked the end of a long black bone. Brunel stepped down from the footboard and delved in the silt and pulled up the bone. I took it from him (it was a humerus), feeling the tin vibrate with a regular tarantella. We went up for air and came straight back down, and Brunel and the labourer began to excavate the two feet or so of silt above the brick arch of the tunnel, and at last uncovered a bundle as long as a man, wrapped in something like the casing of a giant beetle, black and slippery and stinking badly.

It took all three of us to haul it onto the footboard, and when we were done we were dizzy and gasping for breath. Brunel pulled the string, four long strong tugs, and we rose up for the last time and were swung above the deck of the barge; and never more grateful was I to feel sunlight on my face as I ducked under the dripping edge of the bell.

Brunel and I unwrapped the body on a bench in the long shed. The wrapping had once been the hide of some large animal; a few patches of coarse hairs still clung to it here and there. Although it had been cured by centuries in the river mud, it stank horribly, and was as stiff and brittle as if turned to wood. Brunel used his pocket knife to cut away the final leaf, and a slough of black mud slid out, thick as porridge, to reveal a human skeleton. It was missing its right arm, which might have fallen away through a ragged tear in the shroud, and its skull.

Brunel looked at me across the rack of wet bones. "How is your tin?"

"Curiously quiet."

Brunel clapped his hands together in delight. "Then I think we have our prize. The question is, just what do we have?"

"I cannot raise the dead, Mr. Brunel, and there's no ghost or imp associated with these bones. It's a skeleton, no more and no less, of a man who died a long while ago."

"I know little about bones," Brunel said, "but I don't think that ordinary skeletons engender an anxious vitality to one of their stray components. And then there is the matter of the missing head."

"It is a puzzle."

"For every puzzle there is a practical solution. Even in the matters in which you are expert, I hope. We have a skeleton here, and a bit of bone that dances a jig, it is so anxious to be reunited with its fellows. We have the bad dreams of myself and Coffee Joe, and at least half a dozen others who were intimate with this site. We have the water which grew so agitated yesterday, and which exerted a certain power over you, Mr. Carlyle."

"And which also tasted of blood."

Brunel levelled his bright gaze at me. "And blood, I might think, being a vital fluid, might have some importance in these occult matters."

"It is not a matter of the occult, Mr. Brunel. But I do agree that we may have stumbled on something deeper than ordinary ghosts. And there is one more fact we must take into account. This was no ordinary death."

I showed Brunel where the seventh cervical vertebra had been severed by some very sharp blade. "It was a downward stroke," I said, "to judge by the angle of the cut."

"Signifying?"

"He was kneeling, and the man who beheaded him struck from above."

"As in an execution."

"Precisely."

We examined the bones closely. It was the skeleton of someone who had stood well over six feet in life. We found a ring of blackened metal loose on the bone of the forefinger of the left hand; a nick with the blade of Brunel's pocketknife showed that it was gold, and when he polished it with a scrap of cloth, he revealed a name inscribed on the inner face: Ulpius Silvanus. We found the point of an arrow buried in an old, healed wound in the right thigh bone. We found a much-corroded buckle, decorated with a relief of a man wearing a kind of stocking cap and riding a bull.

Ulpius Silvanus had been a tall, strongly-built man who, judging by the arrow-wound, might once have been a soldier. He had been beheaded, but his corpse had not been looted, and he had been wrapped in a shroud of cowhide and tipped into the river, where the tides had at last washed his remains to the spot which, centuries later, the progress of Brunel's tunnel had disturbed. His arm had become detached from the rest of his bones, and two fingerbones had washed into the tunnel through one of the innumerable small seeps at the working face. Coffee Joe had taken it, perhaps as a lucky piece, and caused all the trouble that had followed. Many questions remained, not least of which why the man had been executed, and when. The name inscribed on the ring suggested the Roman era, and Brunel said that he would call on the expertise of a curator at the British Museum, where many of the finds fallen into the excavations had been lodged.

I felt a profound satisfaction. Not only had I taken on my first client, but I had solved the case within two days. I told Brunel that I hoped that now the curse had been lifted the tunnel would soon be completed, so that I would be able to walk its length from one side of the Thames to the other, and assured him of my full attention should there be any problem concerning the interment of the remains.

Brunel solemnly shook his head from side to side, just once. "It is not the end of the matter," he said. "You have forgotten Dr. Pretorius."

"Not at all. The man is dangerous, certainly, and although I have no proof that would satisfy the police I am convinced that he was responsible for the murder of Coffee Joe. But he is a mountebank, Mr. Brunel, no better than the gypsy girl."

"Nevertheless, he found Coffee Joe, and he found you, too."

"I suppose there was the imp," I said reluctantly, and had to explain to Brunel what Dr. Pretorius had left behind in the cellar where Coffee Joe had been murdered.

"He is not entirely a mountebank, then," Brunel said.

"I suppose not. What do you propose to do now?"

"I have strong evidence that someone else has been searching for these bones," Brunel said. "I would very much like you to hear it, Mr. Carlyle, and give me your opinion."

Brunel greeted the old man with no little respect, and asked after Jake. The man carefully folded the newspaper in half and laid it on the scrubbed pine table which took up most of the space of his little kingdom, looked at Brunel over the top of his spectacles, and told him that he would send the pot-boy for him directly, looked at me, looked at Brunel again, and asked what refreshment we would require while we waited.

Brunel said, "We'll take two glasses of the Absolutely Stunning, Mr. Welch, and I hope you'll join us in a little something."

The old man allowed that it was a little early for him, but he'd gladly set aside something to go with his supper, drew into pewter tankards two pints of dark ale, and said, as he handed them through the window, "Your company is always welcome here, Mr. Brunel, but I'm sorry that you should choose to ask in a rogue like Jake Mullins."

"I can promise you there'll be no trouble, Mr. Welch," Brunel said, turning his hat around in his nimble white fingers like an admonished schoolboy.

"It's not trouble I'm worried about," the old man said. "If it was trouble I worried about, I would have closed up the Porter's as soon as I inherited the care of it from my late father. Should trouble stick its nose around the door of my establishment, I deal with it sharply, so that it knows that it has no place here." Here, he gave me a significant look. "My concern is that your invitation will give Jake Mullins the idea that the Porter's is a house he can use regular, and that ain't the case at all."

"I could always find him in his own haunt," Brunel said, with a glance and a smile at me. "The Black Bear, I believe, is his house of choice."

"It's his house of last chance, in my considered opinion, and I wouldn't think of a gentleman such as yourself, and your friend here, troubling to go there."

The old man gave me another significant look, and Brunel said, "I have been tardy in my introductions. My friend is Mr. Carlyle, late of Edinburgh."

"I can't say I know him," Mr. Welch said, "but he's welcome enough, I'm sure. Jake Mullins is another matter. I'll be glad if you make it clear to him that a single pint is all he's due here, today and tomorrow, and any other day for that matter."

Brunel humbly assented to the condition and paid the price of that single pint in advance, and I bought a wedge of cheese and bread to fortify myself after my underwater adventure. We made ourselves comfortable at the window overlooking the river, its broad flood as red as blood in the lingering light of the summer sunset. Swallows and bats were swooping to and fro as they chased insects just above calm surface of the reach of water between the bank and a file of ships anchored stern to bow.

Brunel told me that Mr. Welch had run the establishment for more than forty years, and knew everything worth knowing about any business along this part of the river. "It was he who sent a message about what was seen about the river above my tunnel," he said, "and told me how to contact the man who saw it."

"And what was it he saw?"

"I think you should hear that from him," Brunel said, looking past me and half-rising, "for here he is now."

I turned, and saw not a man at all, but an indistinct figure as hung with ghosts and imps as a battleship on review is hung with flags. The imps clung to his hair and shoulders like a congregation of tiny, spiky black monkeys; the ghosts swirled about him like rags of fog, their filmy faces set with despair and desperation. Several of the strongest glimpsed me, and set up such a fearsome agitation that the entire company promptly exploded all around the room. I jumped up in a hot panic, knocking over my pint-pot, dispatched them all, and fell back into my seat in a swoon as Brunel crossed the room in three strides and grabbed hold of the collar of the grizzled wretch who had been their host.

Brunel, when he was done with Mr. Welch (or rather, when that good man was done with him), sat between us and looked from one to the other, and said, "I suppose you had better tell me what happened, Mr. Carlyle, because I don't believe that Jake here quite knows where he is."

"I know," the man said, "that I needs a doctor."

He was a man in his late thirties, his face seamed and sunburnt, a cap set back on the grey, greasy curls of his head, the knot of the red handkerchief slung around his neck under his vigorous grey beard. His shirt was half-unbuttoned and its sleeves rolled up his muscular brown arms, and his corduroy trousers were so stiff with mud that they could have stood by themselves.

"You'll make do with this for now," Brunel said, handing him a wedge of cheese.

The man looked at it, sniffed it, and finally gnawed at it, looking sideways at me as if afraid that I would take it from him. Brunel was looking at me too.

"I removed his burden," I said. "I can assure you that he will suffer no ill effects—quite the reverse, in fact."

Brunel nodded, and said that he thought he understood.

The man, Jake Mullins, looked up from his gnawing, and said that he didn't understand it at all. After some prompting from Brunel, he allowed that perhaps a doctor wasn't required, at least not at the instant, and the young engineer told me that Jake Mullins was a fisher of men, and so was well matched to me, a fisher of an altogether different kind of intelligence.

"I wouldn't call 'em intelligent," Jake Mullins said. "Not when I finds 'em, anyways."

He seemed much calmer now, and there was purpose in his gaze. He pressed a fist to the small of his back and straightened on his stool with a sigh, and took up his pint pot and drank a good deal of it down in a single draft, wiping his lips and beard with his forearm and sighing again, like a man sinking into the comforts of domesticity after a long day's work.

Mr. Welch, leaning at his little window, took note of that sigh, and said sharply, "Don't you make yourself at home, Jake Mullins, and don't think you'll get more than that pint out of me, either. Whether your business is long or short with these gentlemen, that's all you'll get, so sip it with care."

"Don't you worry," Jake Mullins said cheerfully. "I'm not going to cause you any trouble."

Two regular customers came in just then, greeting Mr. Welch by name, and saving him from making a reply.

Jake Mullins took another (much smaller) draft of beer, and said, "He's all right, is Welchy, except that he is a bit too particular about who deserves his custom. It's my trade that he doesn't like, so it's peculiar, ain't it, that my trade brings me here to talk with you, Mr. Brunel. And with your friend, whoever he may be."

I introduced myself and shook Jake Mullins's hand, which was as hard as any length of black oak in the room.

"A Scottish gentleman," he said. "Perhaps you're a doctor—I know they're famous for their surgeons—which is why you're able to tell me that I'll be 'quite all right.' "

"I see a man who has been labouring under a burden," I said. "And I believe that he is beginning to realise that that burden has been lifted from him."

"Then perhaps you're a clergyman," Jake Mullins said. "You dress like one, saving the backwards collar. If not a clergyman, perhaps a missionary, come to save us poor benighted river rats."

"A clergyman is closer to the mark than a doctor," I said.

"Mr. Carlyle has volunteered to advise me," Brunel said, and produced with a flourish a half sovereign from one of the pockets of his waistcoat. "This is what was agreed, I think: twice your inquest money. And now, if you please, Mr. Mullins, you will tell your story."

Jake Mullins took the coin, rubbed it with a thumb, tasted it, rubbed it again, and shoved it into the pocket of his breeches.

"I'm obliged," he said. "There isn't much to tell, but I'm sure you'll think it worth it."

"It was just three nights ago, I believe," Brunel said, with a fair amount of impatience.

"It was. I was running along the Surrey shore in my little boat, past the wharf that used to service your diggings, when I seen it. A little boat like mine, standing seventy or eighty yards from the shore. I thought at first that Bullhead Harvey was in luck again. I was about to hail him, but then the moon peeped out from behind a cloud, and I saw two things. First, that Bullhead wasn't alone, and second, the man I took for Bullhead weren't him at all, but a man considerably thinner, with a bush, as it looked like, of white hair. The white-haired fellow was in the stern of the boat watching the other man work, and the other man was not someone I cared to make acquaintance of on the river; or any other place, for that matter."

"He was a big man," I said, "with dark skin."

Brunel shot me a glance, and Jake Mullins said, "If you know him, then you know why I hung back. Almost too big for the boat, he was, and either a Nubian or a lascar, with a shaved head, and a neck quite as thick. He'd been leaning over the water when I first spied the boat, but then he stood up, hauling on a kind of chain mounted with hooks. The white-haired gent was talking to him in some queer argot, sounding pretty impatient, and holding on to the thwarts because the boat was rocking from side to side, fit to capsize.

"Presently, all of the chain was in, and the big man took up the anchor and let the boat drift a ways. The white-haired gent leaned over the side, making little passes of his hands, and I thought I saw a blue light burning. It was as if he had set fire to something, except that the flames burned upside down, if you see what I mean—under the water, instead of on it. There was mist or smoke above, swirling about as if trying to make a shape, before it blew away. This operation was repeated two or three times, and at last the white-haired gent hissed some instruction to the big man, who cast the coils of chain over the side again, and let the boat drift again before hauling in the chain—again with no luck, which made the white-haired gent pretty unhappy, I think."

"You had plenty of time to see all this," Brunel said.

"I was safely in the shadow of a jetty, for it's around about obstructions to the river's currents that I most often find what I'm looking for, and I sat still and watched a good while. Not daring to move, you see, in case they spotted me. I'm a strong rower, but that big man, he could have out-pulled a frigate, to my reckoning. So all I could do was watch, until after an hour the white-haired gent slumped back, and the big man took up the sculls and rowed off."

Brunel said, "In what direction?"

"He was rowing against the current, and going faster than any boat I've ever seen. If I had made a run for it, he would have caught me before I'd gone more than a few lengths." Jake Mullins drained his pint. "Well, that's my tale, gents, and I hope it was worth your time and your money."