“No idea.”

“Ranulf Flambard. This was in the year of our Lord eleven hundred and one. Since then very little has changed. The Tower’s inmates refrain from escaping, not because the place is so competently looked after, but because they are mostly English gentlemen, who would look on it as bad form to leave. If the place were managed by Frenchmen our plan would be certain to fail, but as matters stand-”

“Come, they’re not so bad,” Jack put in, “see how the redcoats swarm to the Wharf. The alarm has gone up.”

“Excellent,” de Gex purred. “Then a Russian and a Scotsman may achieve what no Englishman would dream of.”

WHEN NEXT THEY SAW COLONEL Barnes, they were well down the last reach of the Hope. The tide was rushing away from them so ardently that it threatened to ground Atalanta on the floor of an empty Thames. The river drew narrower every minute as its contents fled to the sea, exposing vast gray-brown slatherings to the air. Southend could be seen a few miles off the port bow, stranded in a mud desert. But what dominated the prospect was the sweep of the open ocean, which now subtended a full quarter of the horizon.

To starboard a fat sinuous river could be seen meandering out through the Kent marshes and nearly exhausting itself as it struggled across the ever-widening flat, trying to connect with the Thames.

“It is Yantlet Creek,” announced Colonel Barnes. “All that lies beyond it is not the mainland, but the Isle of Grain.”

“How can a creek form an island?” Daniel inquired.

“Questions such as that are the penalty we suffer for inviting Natural Philosophers,” Barnes sighed.

“Sir Isaac asked, too?”

“Yes, and I’ll give you the same answer.” Barnes unrolled his map, and traced the S of Yantlet Creek inland to a place where it joined up with a ganglion of other creeks, some of which flowed the other direction, into the Medway on the opposite side of the isle.

“Gravity seems to be mocking us here-who can explain the flow of these streams?” Daniel mused.

“Perhaps Leibniz can,” Barnes returned, sotto voce.

“So it is truly an island,” Daniel admitted, “which raises the question: how will your mounted companies be able to cross over to it? I assume that is what they are doing.”

Barnes used one dirty fingernail to trace the line of a road from the ferry wharf at Gravesend eastwards along the foot of the chalk hills. Where the Thames had jogged north to swing round the hammerhead, the road angled south to cut across its narrow handle, and then to follow the higher and drier ground a few miles inland of the Thames. “Here’s where they should have got ahead of us,” Barnes said. “And here is the bridge-the only bridge-over Yantlet Creek to the Isle of Grain.”

“Military man that you are, you lay great stress upon the onliness of that bridge,” Daniel remarked.

“Military man that I am, I have made it mine, for today,” Barnes stated. “My men have crossed over it, and hold the Isle end.” Then he checked his watch, to reassure himself. “Jack and his men are pent up now on that Isle, they cannot escape by land. And if they should attempt it by sea-why, we shall be waiting for them, shan’t we?”

He could learn nothing further from the map, so Daniel looked up. He could now see a rectangular keep sticking up out the top of a cairn-like foundation, perhaps a mile ahead of them.

At high tide, Shive Tor might make, if not a pretty picture, then at least a striking Gothick spectacle, jutting out of sparkling water off the shore of the Isle of Grain, brooding over the traffic of ships through England’s front gate. But at this moment it stood alone in the middle of an expanse of drained muck the size of London.

“If Jack lives up to his reputation, he’ll have a vessel at his disposal-perhaps a bigger and better one than this,” Daniel said-less to raise a serious objection than to egg Barnes on.

“But look beyond-behold what lies in the distance!” Barnes exclaimed.

Daniel now gazed past Shive Tor and perceived that there was water again, a mile or two beyond it. It required a moment or two to persuade himself that this must be the channel of the Medway. On the far bank of that lay a system of fortifications with a fishing-village cowering behind it: Sheerness.

“If Jack breaks for France, we need only signal Sheerness Fort. The Admiralty shall see to the rest,” Barnes said. He said it distractedly, as he’d telescoped a brass perspective-glass to full length and was using it to squint at Shive Tor. “Not to worry, though-as we expected, he’s high and dry. There’s a ship-channel, you see, so that the Tor can be serviced by water, and Jack’s been dredging it deeper and deeper, so he can sail right up to the Tor with larger and larger vessels-but it’s no use during a spring tide. A longboat would scrape the bottom of that ditch this evening.”

Round the time Shive Tor had emerged from behind the Isle of Grain, a new wind had flooded over the starboard bow. For the last few minutes the sailors had been attending to it, trimming the canvas. Their business masked the more subtle operations of signalmen, who were at work with flags trying to communicate (or so Daniel assumed) with the dragoons who had disembarked at Gravesend. There was, in other words, a bit of a lull. Quite obviously, it would not last, and then there was no telling when Daniel would have another opportunity to speak to Barnes.

“Don’t mind Roger,” he said.

“Beg your pardon, sir?”

“The Marquis of Ravenscar. Don’t be troubled. I shall send him a note.”

“What sort of note, precisely?”

“Oh, I don’t know. ‘Dear Roger, fascinated to hear you are raising an army, oddly enough, so am I, and have already invited Colonel Barnes to be my Commander-in-Chief. Do let’s be allies. Your comrade-in-

arms, Daniel.’ ”

Barnes wanted to laugh but could not quite trust his ears, and so held it in, and went apoplectic red. “I should be indebted,” he said.

“Not at all.”

“If my men were to suffer, because of some political-”

“It is quite out of the question. Bolingbroke shall live out his declining years in France. The Hanovers shall come, and when they do, I shall extol you and your men to Princess Caroline.”

Barnes bowed to him. Then he said, “Or perhaps not, depending upon what happens in the next hour.”

“It shall go splendidly, Colonel Barnes. One more thing, before we are embroiled-?”

“Yes, Doctor?”

“Your superior wanted to convey some message to me?”

“I beg your pardon?”

“The Black-guard who accosted you on Tower Wharf this morning.”

“Ah yes,” Barnes said, and grinned. “Great big chap, dark and a bit gloomy, would’ve made a fine dragoon. Spoke in words I did not fully understand. Which was probably his intent. Wanted me to tell you that it was a lay.”

Daniel was frozen for a count of ten.

“You all right, Doctor?”

“This breeze off the sea is quite bracing.”

“I’ll get you a blanket.”

“No, stay… Those…those were his words? ‘It’s a lay’?”

“That was the entire message. What’s it signify? If you don’t mind my asking.”

“It means we should all turn around and go back to London.”

Barnes laughed. “Why’d we want to do such a thing, Doctor?”

“Because this is a trap. No, don’t you see? They somehow-Jack somehow-knew.”

“Knew what, Doctor?”

“Everything. He led us on.”

Barnes took a moment to think it through. “What, you’re saying the Russian was planted?”

“Just so! Why else would he have divulged so much, so soon?”

“Because Charles White had his testicles in a vise?”

“No, no, no. I’m telling you, Colonel-”

“Too fanciful,” was the verdict of Barnes. “More likely, the Black-guard’s in the pay of Jack, and, in a last-ditch gambit to stop us from coming out here, tried to scare us off with words.”