Barnes stood up in the boat, putting all his weight on his one leg and bracing his peg against a bench. He cupped his hands round his mouth and bellowed towards the darkling isle: “Turn back! Retreat! There is not room for you here!” And then he fell back on his arse as the boat was lifted and shoved by a tidal swell. “I do not wish to hear my First Company being drowned,” he said.

“Colonel, let us row toward the Isle of Grain-you can warn them all, and rescue most,” Daniel suggested.

“Leave me on yonder vessel,” Isaac demanded, gesturing toward the hooker, which was now upright and adrift.

“I cannot abandon Sir Isaac Newton on a derelict fishing-boat!” shouted Barnes, exasperated.

“Then do you stay with him, Colonel,” suggested Sergeant Bob, “and take a few men. I’ll row toward the land, advancing with the tide-warning the men off as I go, rescuing the mired.”

A thud and crackle from the Tor as a floor-beam gave way. A billion orange sparks spewed from the openings and schooled in the dark.

“I too shall remain with Sir Isaac,” Daniel heard himself saying, like a man lying in state, listening to his own eulogy. “We’ll get the hooker clear of the fire, and navigate by the stars. Sir Isaac and I have some knowledge of the stars.”

“FIRE,” SAID JACK, down on a knee, perspective glass steady on the railing.

This command-given in a mild conversational tone-was not answered with the expected hellish noises and exhalations. He peeled his eye from the lens and was abruptly reminded that he was two hundred feet above London. A bad time for a dizzy spell. He spanked the railing, clenched his eyes shut, and announced: “The Scotsman is inside the White Tower; I say, Fire!” Then he opened his eyes, got up, and backed round the stony bole of the Monument, for these things were as likely to explode as to fly. He heard Jimmy and Danny murmuring to each other, then a sputter as the fuse caught, then running feet. The lads came into view. Immediately a basilisk-sound, half hiss and half scream, erupted on the other side and rapidly dwindled.

Jack ran around to see a ray of black fog cantilevered out over the city. On the near side its billows were weirdly lit up, like a squall-line at sunset. But this paled and dissolved in a few moments. The only evidence that remained of this grievous and execrable crime against all known precepts of safe rocketry was a house with a hole in its roof, just short of Mincing Lane, and a gossamer thread connecting said hole with the large pulley lashed to the lantern of the Monument above their heads. From there it ran almost straight down into a polished copper kettle about three paces away from Jack, between the feet of a large Red Indian. The Indian grabbed the thread in one hand lest all of what remained be sucked from the kettle by its own weight.

Jack looked over the railing and saw the filament plunge down and away toward the east. He lost track of it in the Monument’s shadow. But he could see a lot of boyish ferment on the roof of the Church of St. Mary-at-Hill, five hundred feet away: some leaping, some hopping into the air, some hurling of stones with strings tied to ’em. To any observer who did not know, as Jack did, that a thread of silk was floating in the air a few yards above these people’s heads, it would have looked like the cavorting of men and boys made mad by witchcraft or syphilis, a kind of Bedlam al fresco.

A distant rocket-scream sounded from near the Tower of London. Such was the speed of this second rocket’s flight that by the time its sound carried to the top of the Monument, and drew Jack’s gaze that way, it was gone, and there was nothing to be seen but a black rainbow bent over Tower Hill and the Moat, connecting the Barking Churchyard behind All Hallows Church to the battlements of the White Tower. “Not a pot of gold, but close to one,” Jack remarked. He was fortunate enough, now, to be looking in the right direction to see yet another dart of white flame jump up from the River Thames, pulling a shroud of black powder-smoke behind it. It reached apogee above Tower Wharf and then winked out. Momentum carried it north over the Outer Wall to crash in Tower Lane. “Damn, too short!” Jack cried, as the sound of the launch reached them.

“They’ve spares on the barge, Dad,” Danny said.

He glanced down onto the Church of St. Mary-at-Hill. The men and boys on the roof had settled down noticeably-in fact, most of them were running away, which was, of course, the normal practice, from the scene of their crimes. Only two remained. One was working on his lap. The other was acting as a sort of lookout. He needn’t have bothered; the rocket that had screamed over his head a few moments ago had ignited a fire in the attic of that house on Mincing Lane, and there, rather than the church’s roof, was where the attentions of the (paltry number of mostly self-appointed) authorities and the (vastly more energetic and numerous) Mobb were now directed.

The one who had been working on his lap suddenly sprang back, jumping to his feet, and elevated his chin, as if he had released a carrier pigeon and were watching it take flight. The Indian beside Jack began to pull in string, hand-over-hand, as rapidly as he could. “Look out below!” called Jimmy, as he picked up the copper string-vat and simply dropped it over the rail.

A curse from Danny: “Hit the Lanthorn Tower this time.” Then another whooshing scream from the river. Jack glimpsed another smoke-prong in the distance.

The kettle made a funny noise, a cross between a splat and a bong, as it hit the pavement below them. Tomba was grinning beneath a perspective glass. “Men in kilts on the battlements of the White Tower,” he announced.

“And just what are those men doing?” inquired Jack, whose attention was fixed on the roof of the church of St. Dunstan-in-the-East, where a scene had just played out remarkably like that moments earlier on the roof of St. Mary-at-Hill.

“It appears that they are drinking usquebaugh and line dancing,” returned Tomba.

“One day your wit shall be the death of you, and my hands around your throat shall be the instrument,” Jack remarked calmly.

“Some of them are pulling in the string from Barking Churchyard,” Tomba returned, “others raising a banner.”

“Raising a banner!? I gave no instructions touching a banner,” Jack hollered.

“A Cross of St. Andrews, and-”

“Oh, Jesus Christ. Is any of those Highlanders concerning himself with a pulley?”

“The pulley is being worked on-hold-oh, my God!” Tomba exclaimed, and drew back from the perspective glass laughing.

“What is it?”

“The rocket. It nearly knocked one of them down,” Tomba explained, as yet another basilisk-shriek reached them from the river.

“So the last one flew true?”

“Skipped across the roof of the White Tower itself like a flat stone on a pond,” confirmed Danny, who had watched with his naked eyes. “Passed between a Scotsman’s legs and smacked into the north parapet.”

“I hope that the Scotsman has had the presence of mind to stomp on the string.”

“They appear to be pulling it in-there’s a chap working by the pulley now-good! The pulley is threaded-”

“The roof of Trinity House is cleared!” Tomba mentioned, having trained his spyglass on a building halfway between them and the White Tower.

“Take up the slack smartly now!” Jack called down over the railing. He was awash in fiery light up here. The men at the base of the column were toiling in blue dusk, pulling in loose thread from above as fast as their hands could move. They were working in a clear space, a sort of defensive perimeter that had been set up round the base of the column. Around it the black lint of the Mobb was rapidly gathering, kept at bay by very large hoodlums with whips, and archers who had scaled the plinth of the great column to take up sniping-positions under the wings of its dragons.