While Isaac Peckham was fleeing through the blood-soaked woods of eleventh-century Sussex, seven hundred and ten years in the future the Reverend Doctor Nevil Maskelyne sat behind the bolted oak doors of his private study at the Royal Greenwich Observatory.
Outside, a pale April sun was rising over the curve of the Thames, glinting off the twin domes of Christopher Wren’s naval hospital below the hill. Inside the room, the heavy velvet curtains were drawn tight, and a single silver candelabrum burned upon the green baize table.
Before the Astronomer Royal lay the greased oilskin bag he had pulled from John Harrison’s kitchen drain, and beside it rested the duplicate gold timepiece. Maskelyne had dismissed Corporal Brent and Private Cobb to the barracks below with strict orders that he was not to be disturbed before noon, not even if King George himself rode into the courtyard. His small, bloodshot eyes were fixed upon the walnut-sized glass chamber mounted at the crown of the watch.
‘So this is your final trick, John,’ Maskelyne whispered, lifting a jeweller’s loupe to his right eye and bending low over the casing. ‘No lunar tables. No sextants. Only a conjurer’s stone from the Malabar dirt.’
Through the magnifying lens, he could see that the timepiece was a marvel of miniature engineering. The three knurled brass wheels protruding from the right-hand bezel were engraved with microscopic numerals—not hours, minutes, and seconds, as on the marine chronometers Harrison had submitted to the Board of Longitude, but degrees of arc and logarithmic increments running both forward and backward from a zero-mark.
Inside the thick quartz bulb at the top, the multifaceted crystal sat suspended between two tiny jaws of insulated gold wire connected directly to the mainspring barrel. Even at rest, the heart of the stone was not wholly dark; a faint, smoky luminescence drifted within its facets like milk stirred into dark water.
Maskelyne’s stubby fingers trembled with an unholy mixture of scientific greed and theological dread. He had seen the apprentice boy twist that upper glass chamber in the kitchen at Red Lion Square—and he had seen the lad plucked clean out of the physical world in a flash of blue lightning.
What he did not know—what he had no way of knowing—was that this second watch was the prototype John Harrison had used during his secret trial just before Christmas, and that the old clockmaker had never reset the three brass coordinate wheels after dragging himself scorched and half-dead across his study floor. The dials were still locked to the maximum backward limit of the scale: a primordial epoch billions of years before the first blade of grass took root upon the earth.
Unable to restrain his curiosity another moment, Maskelyne gripped the heavy gold case in his left palm, pinched the glass chamber between thumb and forefinger, and gave it a sharp quarter-turn to the right. At once, the crystal inside began to spin.
A low, metallic hum vibrated through the gold casing into the bones of Maskelyne’s wrist. Blue sparks danced across the engraved bezel. Before the Astronomer Royal could release his grip or cry out, the room around him dissolved in a silent, blinding detonation of white fire.
The green baize table vanished. The bookshelves of the Octagon Room were ripped away as though torn from a painted stage-cloth.
Maskelyne hit jagged, blistering rock on his hands and knees.
When he opened his eyes and drew breath, he screamed—for the air he sucked into his lungs was a furnace of superheated steam, choking black ash, and raw, suffocating sulphur.
All around him, beneath a sky the colour of clotted blood, the earth was splitting open. Great rivers of incandescent orange magma sluggishly carved their way through plains of black basalt. Half a mile away, a volcanic cone erupted with a sound that nearly ruptured his eardrums, hurling boulders the size of cathedrals into a lightning-riven firmament.
There were no trees, no seas, no stars—only fire, brimstone, and the deafening roar of a world in torment.
The extreme radiant heat blistered the skin of Maskelyne’s cheeks and hands in seconds. His fine velvet coat began to smoke at the hems; his powdered wig singed and shrivelled round his ears. Clawing at his throat as his lungs seized in the poisonous gas, the Reverend Doctor Nevil Maskelyne collapsed face-down upon the scorching stone, clutching the burning gold watch to his chest and shrieking a prayer for mercy— utterly convinced that he had been cast alive into the pit of Hell.
Only the safety catch John Harrison had built into the prototype’s mainspring saved the Astronomer Royal from dying beside a Hadean volcano. Designed to unwind and snap back to its point of origin after ninety seconds of displacement, the internal ratchet clicked home.
A second flash of blue-white light swallowed the magma plains.
With a heavy thud and a billow of sulphurous smoke, Nevil Maskelyne crashed back onto the Turkish carpet of his study at Greenwich, rolling over and over as he beat wildly at his smoking coat-sleeves and retched onto the floorboards.
For ten minutes the Astronomer Royal lay shivering on his floor, weeping with terror, his hands and jowled face raw and scarlet as beefsteak, while the stench of brimstone filled the Octagon Room.
Slowly, painfully, he dragged himself up by the leg of his desk and stared at the gold watch lying upon the rug.
‘The Devil…’ Maskelyne wheezed through blistered lips, reaching for his decanter of brandy with a shaking hand. ‘Harrison was in league with the Devil himself. That stone opens the gates of Perdition.’
Yet even as he drank the brandy down in great, gulping mouthfuls, the cold, calculating pride that had driven Nevil Maskelyne all his life began to reassert itself over his terror. He had stepped outside the bounds of mortal time—even into the fires of the Pit—and he had returned alive. If the three brass wheels on the flank of the watch governed the distance of the journey, then they could be calculated, charted, and mastered just like the motions of the moon.
And out there, somewhere in the centuries, an illiterate Post Office brat was wandering loose with the twin of this machine.
Limping to the bell-pull, Maskelyne rang furiously for Corporal Brent. He would have salve brought for his burns, he would decipher Harrison’s wheel-ratios down to the last tooth—and then he would hunt Isaac Peckham to the ends of time.
