Just short of St. James’s Palace, the carriage turned left onto Pall Mall, and began to move up in the direction of Charing Cross.

“Light-bearer? What’s that?” Pepys asked.

“A new elemental substance,” Wilkins said. “All the alchemists on the Continent are abuzz over it.”

“What’s it made of?”

“It’s not made of anything -that’s what is meant by elemental!”

“What planet is it of? I thought all the planets were spoken for,” Pepys protested.

“Enoch will explain it.”

“Has there been any movement on the Royal Society’s other concern?”

“Yes!” Comstock said. He was looking into Wilkins’s eyes, but he made a tiny glance toward Daniel. Wilkins replied with an equally tiny nod.

“Mr. Waterhouse, I am pleased to present you with this order,” Comstock said, “from my Lord Penistone,”*producing a terrifying document with a fat wax seal dangling from the bottom margin. “Show it to the guards at the Tower tomorrow evening-and, even as we are at one end of London, viewing the Phosphorus Demo’, you and Mr. Oldenburg will be convened at the other so that you can see to his needs. I know that he wants new strings for his theorbo-quills-ink-certain books-and of course there’s an enormous amount of unread mail.”

“Unread by GRUBENDOL, that is,” Pepys jested.

Comstock turned and gave him a look that must’ve made Pepys feel as if he were staring directly into the barrel of a loaded cannon.

Daniel Waterhouse exchanged a little glance with the Bishop of Chester. Now they knew who’d been reading Oldenburg’s foreign letters: Comstock.

Comstock turned and smiled politely-but not pleasantly-at Daniel. “You’re staying at your elder half-brother’s house?”

“Just so, sir.”

“I’ll have the goods sent round tomorrow morning.”

The coach swung round the southern boundary of Charing Cross and pulled up before a fine new town-house. Daniel, having evidently out-stayed his relevance, was invited in the most polite and genteel way imaginable to exit the coach, and take a seat on top of it. He did so and realized, without really being surprised, that they had stopped in front of the apothecary shop of Monsieur LeFebure, King’s Chymist-the very same place where Isaac Newton had spent most of the morning, and had had an orchestrated chance encounter with the Earl of Upnor.

The front door opened and a man in a long cloak stepped out, silhouetted by lamplight from within, and approached the coach. As he got clear of the light shining out of the house, and moved across the darkness, it became possible to see that the hem of his cloak, and the tips of his fingers, shone with a strange green light.

“Well met, Daniel Waterhouse,” he said, and before Daniel could answer, Enoch the Red had climbed into the open door of the coach and closed it behind him.

The coach simply rounded the corner out of Charing Cross, which put them at one end of the long paved plaza before Whitehall. They drove directly towards the Holbein Gate, which was a four-turreted Gothic castle, taller than it was wide, that dominated the far end of the space. A huddle of indifferent gables and chimneys hid the big spaces off to their left: first Scotland Yard, which was an irregular mosaic of Wood Yards and Scalding Yards and Cider Houses, cluttered with coal-heaps and wood-piles, and after that, the Great Court of the Palace. On the right-where, during Daniel’s boyhood, there’d been nothing but park, and a view towards St. James’s Palace-there now loomed a long stone wall, twice as high as a man, and blank except for the gun-slits. Because Daniel was up on top of the carriage he could see a few tree-branches over its top, and the rooves of the wooden buildings that Cromwell had thrown up within those walls to house his Horse Guards. The new King-perhaps remembering that this plaza had once been filled with a crowd of people come to watch his father’s head get chopped off-had decided to keep the wall, and the gun-slits, and the Horse Guards.

The Palace’s Great Gate went by on the left, opening a glimpse of the Great Court and one or two big halls and chapels at the far end of it, down towards the river. More or less well-dressed pedestrians were going in and out of that gate, in twos and threes, availing themselves of a public right-of-way that led across the Great Court (it was clearly visible, even at night, as a rutted path over the ground) and that eventually snaked between, and through, various Palace Buildings and terminated at Whitehall Stairs, where watermen brought their little boats to pick up and discharge passengers.

The view through the Great Gate was then eclipsed by the corner of the Banqueting House, a giant white stone snuff-box of a building, which was kept dark on most nights so that torch- and candle-smoke would not blacken the buxom goddesses that Rubens had daubed on its ceiling. One or two torches were burning in there tonight, and Daniel was able to look up through a window and catch a glimpse of Minerva strangling Rebellion. But the carriage had nearly reached the end of the plaza now, and was slowing down, for this was an aesthetic cul-de-sac so miserable that it made even horses a bit woozy: the old quasi-Dutch gables of Lady Castlemaine’s apartments dead ahead; the Holbein Gate’s squat Gothic arch to the right and its medieval castle-towers looming far above their heads; the Italian Renaissance Banqueting House still on their left; and, across from it, that blank, slitted stone wall, which was as close as Puritans had ever come to having their own style of architecture.

The Holbein Gate would lead to King Street, which would take them to a sort of pied-a-terre that Pepys had in that quarter. But instead the driver chivvied his team around a difficult left turn and into a dark downhill passage, barely wider than the coach itself, that cut behind the Banqueting House and drained toward the river.

Now, any Englishman in decent clothing could walk almost anywhere in Whitehall Palace, even passing through the King’s ante-chamber-a practice that European nobility considered to be far beyond vulgar, deep into the realm of the bizarre. Even so, Daniel had never been down this defile, which had always seemed Not a Good Place for a Young Puritan to Go-he wasn’t even sure if it had an outlet, and always imagined that people like the Earl of Upnor would go there to molest serving-wenches or prosecute sword-duels.

The Privy Gallery ran along the right side of it. Now technically a gallery was just a hallway-in this case, one that led directly to those parts of Whitehall where the King himself dwelt, and toyed with his mistresses, and met with his counselors. But just as London Bridge had, over time, become covered over with houses and shops of haberdashers and glovers and drapers and publicans, so the Privy Gallery, tho’ still an empty tube of air, had become surrounded by a jumbled encrustation of old buildings-mostly apartments that the King awarded to whichever courtiers and mistresses were currently in his favor. These coalesced into a bulwark of shadow off to Daniel’s right, and seemed much bigger than they really were because of being numerous and confusing-as the corpse of a frog, which can fit into a pocket, seems to be a mile wide to the young Natural Philosopher who attempts to dissect it, and inventory its several parts.

Daniel was ambushed, several times, by explosions of laughter from candle-lit windows above: it sounded like sophisticated and cruel laughter. The passage finally bent round to the point where he could see its end. Apparently it debouched into a small pebbled court that he knew by reputation: the King, in theory, listened to sermons from the windows of various chambers and drawing-rooms that fronted on it. But before they reached that holy place the driver reined in his team and the carriage stopped. Daniel looked about, wondering why, and saw nothing except for a stone stairway that descended into a vault or tunnel beneath the Privy Gallery.