“ ’S al’right, sir,” Saturn called, “they’re with us.”

“And who the hell are you?”

Daniel silenced Saturn with a hand on his shoulder, and gave the answer: “Sir Isaac Newton, the Master of Her Majesty’s Mint, investigates an act of High Treason. You are impeding his deputies. Pray stand aside.”

Isaac was as startled to hear this, as was the indigo-suited maniac-wrangler, and stepped up to the railing. He did this not for effect, but simply to see what in heaven’s name was going on. But the apparition of the ancient white-haired sorcerer-knight struck the attendant, and moved him aside, like a blast of wind blowing a door open. “I do beg your pardon, guv’nor,” he said, in a much more moderate tone, after Saturn’s ruffians had filed past him. “Is there any way I can be of service?”

“Prevent sight-seers from coming up here, thank you,” Daniel returned, then wheeled round and began to scan the walls. This upper storey was not as prized by the Governors of Bedlam as it had been by Hooke; rather than situating their best offices here, they had sprinkled tables and trunks about the place, making it into a dovecote for clerks, and a dump for little-used documents.

“When we were here for my party it looked much as it does now,” Daniel said to Isaac, “which is to say that these inward-sloping walls-which are, of course, the inner surface of the roof’s structure-had been plastered over.”

“Yes.”

“But I often visited Hooke here much earlier-back in the seventies. This part of Bedlam went up first-as you’ll recall, the wings took years to complete.”

“Yes.”

“I am trying to recollect what it looked like, before lath and plaster were put up. I phant’sy that behind these surfaces are large cavities-particularly-if memory serves-here, between where the chimney is hidden as it pierces the roof, and the corner. There are four chimneys-hence, four such cavities.” Daniel had been dragging a hand along the plaster as he spoke, occasionally thumping with his knuckles. He’d stopped at a place, near the corner, where it answered with an especially resonant boom. Without allowing his hand to move, he turned round now to scan the other three corners. His gaze lit on one that was stained with fresh plaster. Then-fortuitously-he noticed that Timothy Stubbs had finally caught up with them.

Pleasantly baffled might have described Stubbs’s state of mind when he’d reached the head of the stairs; horrified was nearer the mark now. Daniel favored him with a thin smile. “Does my discourse have a familiar ring to you, Mr. Stubbs?”

“Indeed, Doctor, it is very like what John Doe was saying to his confederates, after I followed them hither that night.”

“You showed commendable nerve, Mr. Stubbs, in sneaking up on a gang of madmen.”

The praise caused Stubbs to relax a bit. “Wish I’d been so cool as to’ve tackled all of ’em, guv.”

“You did just the proper thing by capturing their leader. Is that the place, over yonder, where they attacked the wall?” Daniel asked, pointing to the fresh plaster.

“Indeed, sir.”

“Mad as hatters-or so ’twould seem,” Daniel mused. “On the other hand, suppose there really is treasure, or something, hidden in one of these corners. Then John Doe is no madman, but a burglar or worse; and all of the treatments I have prescribed for him are to no purpose. They might even be detrimental! He should in that event be at Newgate awaiting justice, not at Bedlam seeking a cure. The only way to be certain is to look. I take it that Doe found nothing, when he broke through the wall?”

“Wasps’ nests and bat droppings only,” Stubbs returned, speaking slowly, as he was a bit lost.

“That is not surprising. Mr. Hooke would have placed his cache in the corner most sheltered from the prevailing winds-there,” Daniel said, and pointed along the wall to the next corner. Saturn looked at him, and Daniel nodded. Saturn turned his back to the others and sauntered to the corner indicated. He gave his right arm a little twitch as he went, and a loggerhead of black iron dropped out of his sleeve, fat end first. His fingers closed round the narrow end just in time to keep it from dropping to the floor. Then with a sudden movement he brought it diagonally up and across his body, and with a ponderous swing of his whole trunk delivered a massive back-hand blow to the wall. The loggerhead burst through the plaster and the underlying lath like a musket-ball piercing a melon. Saturn drew it out, transferred the loggerhead to the other hand, and shoved half of his arm through the hole.

Mr. Timothy Stubbs was not in the least pleased by any of this, and looked as though the only thing preventing him from adding Saturn to Bedlam’s roster was the implicit threat of the four lads Saturn had summoned up. But Peter Hoxton quickly settled the issue by declaring: “The verdict is in. John Doe is no lunatick, but a common burglar.” And he drew his arm out of the hole, and held up, as proof, a rolled sheaf of dusty papers. “Or perhaps an uncommon one.”

“ ’TWOULD APPEAR YOU HAD WARNED Mr. Stubbs to be on alert for madmen who would wish to knock holes in the walls,” Isaac said, “but how could you have anticipated this?”

He and Daniel had retreated to the opposite corner of the upper storey to get away from the dust and noise created by the assault on the wall. Saturn’s lads, who had come with diverse crowbars, steve-dore’s hooks, amp;c., secreted on their persons, had demolished a few square yards of plaster and lath, exposing a prism of dark space in which two or three bodies might have been concealed, if Hooke had been that sort of chap. Instead, he had packed in two wooden trunks, and a few leather wallets, then caulked the interstices with wadded or rolled papers. The dust was now settling to the point where Daniel and Isaac were tempted to approach. But first Isaac wanted an explanation.

“The story is not wholly known to me,” Daniel said. “Several of Hooke’s buildings, including the Royal College of Physicians and my lord Ravenscar’s house, have recently been invaded.”

“Catherine told me about the attack on her domicile,” Isaac said. “A queer lot of burglars they were-knocking holes in my lord Ravenscar’s walls to discover naught, while ignoring treasures that were sitting out in plain view.”

“Simple extrapolation told me that Bedlam might be next. I paid Mr. Stubbs to show especial vigilance. John Doe was captured a week ago. He has done his utmost, I am told, to keep up the facade of a raving lunatick. Now that he knows what treatment lunaticks may expect in Bedlam, he may confess to simple burglary.” Daniel caught Stubbs’s eye-which was not easily done, as Stubbs was paralyzed with astonishment to see what was being dragged out of the walls. “Pray go to John Doe’s cell. Tell him nothing about what has really occurred. Rather, tell him that Dr. Waterhouse has knocked holes in all four corners, and found nothing-proof that Doe is a madman indeed, who may, therefore, look forward to a stay here of indefinite duration.”

Peter Hoxton had been carrying out a rough sort of the booty from the wall. Which was to say, he had raked out all that was of Saturnine interest and put the discards in another, larger pile. He had already culled out enough to keep him rapt for weeks: for the trunks were packed with small wooden chests, and the chests with fine instruments wrought of brass, and even of gold. Many of these were obviously clock-work. Saturn, wary of the dust, peered quickly at these, then closed them up and stacked them out of harm’s way, covering them with a large drawing which he pressed into service as a tarpaulin. But the drawing itself-a phantastickal rendering of the skeleton of a bird-had now cozened him into rigid fascination. Isaac too was drawn to it. “I thought it were a rendering of a bird, at first,” Saturn said, “until I spied this cull-” and he pointed to a snarl of lines that Hooke had, over the course of a few seconds’ lazy yet furious drawing, scrawled and slashed onto the page. These by some miracle added up to a perfectly intelligible rendering of a man in breeches, waistcoat, and periwig, standing with arms raised above his head to support one joint of the wing. If this was supposed to be a bird, it would have a wingspan several times that of the largest albatross. But where a bird would have muscles to pull, this skeleton had pistons and cylinders to push, the great bones of the wings. It was inside-out and backwards, exoskeletal.