It was twenty to five on the afternoon of Tuesday, 15 June 1920. In the basement of the Fenwick Laboratory in London, two men were running an experiment. The room smelled of hot shellac and of Professor Hartley's pipe. On the bench, the needle of the galvanometer, the dial that measured the current, had started to climb.
"Read it out," said Hartley.
"Four point two," said John. "Four point four."
"Lovely." Hartley was kneeling on the floor beside the coil housing with a screwdriver held in his teeth, so lovely came out as luvvy. He took the screwdriver out. "Keep reading. If we're finished by seven, I can get home in time for Melba."
"For what?"
"Dame Nellie Melba. She's singing on the wireless from Chelmsford at ten past seven. Singing into the air." He waved the screwdriver at the ceiling.
"Four point nine," said John.
The machine was called the resonance stabiliser, and it took up most of the bench. It had two copper coils, each the size of a bicycle wheel, which John had wound by hand over three wet weeks in March. Between the coils, a flat plate of quartz sat in a clamp. Beside them, a mercury interrupter ticked in a glass jar. Under the bench stood racks of sixty Leclanché batteries, each labelled in John's small, square handwriting. On top of the paper chart roll, to stop it curling, lay Hartley's astrolabe. It was a brass disc as wide as a saucer, gone green in the grooves, with a star map cut out of a top plate over a bottom plate of engraved lines. Hartley had bought it in a shop on the Charing Cross Road for nine shillings because nobody else wanted it.
The needle went past five.
"Five point three," said John. "Professor. That's past the line."
"It's meant to go past the line. That's the experiment."
"It's past the line you drew on the dial yesterday."
Hartley looked up. He was sixty-one, bald on top, with white tufts of hair over his ears and small bright eyes behind steel spectacles. He gave John the look he always gave him when John was being careful: fond, and with no intention of listening.
"John," he said. "You've been in a war. Nothing in this room is going to blow up."
The quartz plate began to make a sound.
It was a thin, very high note, like a wet finger rubbed round the rim of a glass. The mercury interrupter stopped ticking and began to hum. The hairs on John's arms stood up under his shirtsleeves. Under the smell of shellac and pipe smoke there was a new smell, clean and sharp. John knew it from the wireless dugouts at Messines during the war. It was the smell just before a valve burned out.
That's ozone.
"Five point eight," he said. "Six. Professor, I'm opening the..."
He reached for the knife switch to cut the power. It was a hinged copper blade with a wooden handle, pressed down into a metal clip; pulling it up would break the circuit. Before his hand got there, a white flash filled the whole room.
* * *
John had been hit by a shell once, at Wytschaete. That had been a hard shove, a roar, and then the ground. This was different. It was silent. It felt as if the room were falling away from him in every direction at once.
Then he saw the basement again.
But it was not the basement he was standing in. It had the same walls and the same low, arched ceiling with the pipes running along it, but now the walls were painted white. Long glass tubes on the ceiling gave off a flat, bluish light, like no lamp he had ever seen. The bench was gone. In its place stood a grey metal cabinet with a dark glass window in the front, and small lines of green light moved across the glass. On a table by the door stood a paper cup with a lid, and there was red lipstick on the lid. On the wall hung a calendar with a photograph of a mountain. It said MARCH 2045.
He was seeing the same room, a hundred and twenty-five years in the future.
Somewhere behind him, a woman's voice said quite clearly, "Oh, come on."
Then the basement vanished. John was standing on nothing, high in the air, looking down at a city.
The city lay beside a sea of a blue he had only ever seen in paintings. Glass towers rose out of it, taller than St Paul's Cathedral. Straight roads ran between them, full of fast, bright shapes. On the side of the nearest tower hung a picture of a woman's face, three storeys high. Next to it was a line of writing he couldn't read: little birds, eyes and wavy lines, like the writing on the mummy cases in the British Museum. Under the writing, in ordinary numbers, it said 2002.
Then he saw nothing at all.
* * *
"John. John. Can you hear me? Open your eyes, there's a good chap."
He opened his eyes.
He was lying on his back on the basement floor. Above him were the ceiling and the pipes, and the ordinary yellow light of the electric bulbs. One bulb was swinging gently on its cord. Hartley was bent over him, his face upside down, very close and very white.
"There you are," said Hartley. His voice was shaking. "There you are. Don't move. You've had a nasty shock. The whole battery bank blew. I've pulled the switch."
John sat up anyway.
Blue smoke curled under the arches of the ceiling. The copper coils were burned black. The quartz plate had cracked straight across in its clamp.
And John was seeing everything twice.
Over the real room lay a faint second picture, like a photograph accidentally printed twice on one plate. The real Hartley knelt in front of him. Just to the left, faint and see-through, a second Hartley was standing up. Further left, fainter still, a third Hartley stood at the door. They were not ghosts. They were where Hartley was about to be.
"What time is it?" said John.
Hartley looked at his watch. "Ten to five. You were out for four or five minutes." He frowned. "Why?"
"What's the date?"
"The fifteenth of June. Nineteen-twenty." Hartley frowned harder. "John, you're frightening me."
John watched the faint Hartley by the door. It turned its head. One second later, the real Hartley turned his head the same way, towards the stairs, as if he had heard a noise. But there had been no noise yet. Then it came: a door slammed, two floors up.
He's going to look at the door. Now he's looking at the door. John was seeing a second into the future.
"Professor," said John. "I think something's happened to me."
* * *
He showed Hartley with a pencil.
It was the first thing he could reach: a stub of HB pencil from the bench, with John's teeth marks on the end. He held it out at arm's length over the stone floor and let go. As it left his fingers, he pushed. He didn't push with his hand. He pushed with something behind his eyes, in a direction he had no name for.
The pencil stopped.
Not completely. It was still falling, but only a hair's breadth at a time, turning very slowly end over end, with the light sliding along its yellow paint. The blue smoke under the ceiling had stopped curling and hung in the air like cotton wool. The swinging bulb had stopped at the top of its swing. Hartley's mouth was open in the middle of a word, and the word was taking a very long time to come out. The whole room had slowed down. John had not.
John counted. One. He could hear his own heart, slow and heavy in his ears. Two. His fingertips went cold, as if he had pushed his hands into snow. Three. He felt something warm on his upper lip. Four.
Time snapped back to normal. The pencil hit the floor and bounced. The bulb swung. The smoke curled. Hartley finished his word, which was "...wrong?"
John's nose was bleeding onto his shirt.
He wiped it with the back of his hand and looked at the blood. His fingers had gone white up to the second knuckle, the way a sentry's fingers went after a night on guard in January. And he was hungry. It was the hunger he remembered from the front line in 1917, when the ration party failed to come up for two days.
"There are sandwiches in your bag," he said. "Aren't there?"
Hartley fetched his bag without a word. Inside were two egg and cress sandwiches his housekeeper had made. John ate both of them standing up, in about a minute.
"The pencil," Hartley said at last.
"Yes."
"It stopped."
"It slowed down. Or I sped up. I don't know which." John wiped his mouth. "Four seconds. I counted. And it costs something. Body heat, I think. And whatever food gives you."
"Do it again."
"I don't think I should."
"Do it again, John."
He did it again, while Hartley held a stopwatch. By John's count it lasted four seconds. By the stopwatch it lasted one fifth of a second. His nose bled again, and his teeth started to chatter with cold.
Hartley stared at the stopwatch for a long time.
"Twenty to one," he said. Every second of John's was a twentieth of a second for everyone else. "Good God, John. Do you understand what this is?"
"No."
"Neither do I. Isn't it marvellous?" He was already sitting at his desk with his fountain pen. "We'll write it up tomorrow. And I'll send a telegram to Pyle."
John felt his stomach turn over, slowly.
Major Pyle sat on the War Office board that funded the laboratory. He was a pleasant man in a good grey suit who visited twice a year and asked whether any of their work could be used to find submarines. The War Office paid for the coils, the batteries, and most of John's wages.
"Professor," John said. "Don't."
"Don't what?"
"Don't tell Pyle."
Hartley turned round in his chair with the pen still in his hand. "Why ever not? He'll want to know. He'll have to know. If a man can do what you just did..."
"If a man can do what I just did," said John, "the army will want him back in uniform by Friday. I was a wireless sapper for two years, Professor. They didn't want wireless so people could listen to Melba. They wanted it to aim the big guns. I'm not doing that again. Not with this."
For three years Hartley had been kind to John. He had lent him books, fed him on Sundays, and never asked about the war. But he had also never in his life come near a discovery this big.
"John," he said gently. "This is bigger than Rutherford splitting the atom. We can't keep it quiet because you had a bad war." He put the cap back on his pen. "I'll send the telegram in the morning. You'll see. He'll be sensible."
He got up and reached for his hat on the hat stand.
* * *
Later, John told himself he hadn't really decided to do it. But he had. It just took less time than deciding usually took.
He pushed. The room slowed down, and Hartley's hand stopped in mid-air, halfway to his hat.
This time John looked at Hartley the way he had looked at the pencil, and he saw more than he meant to see.
He could see the last few minutes of Hartley's memory, laid out in front of him like a strip of cinema film: the hanging pencil, the sandwiches, Hartley saying Good God, John, the fountain pen, the name Pyle. Each moment was a separate frame, and John could feel where the frames were joined together.
He found the frame where the pencil test began. He found the frame where Hartley reached for his hat. He took hold of the strip of memory between those two points, the way you would take a piece of film out of a projector, and pulled it out.
It came away. It came away far too easily. And it pulled another memory out with it, one that wasn't part of today.
John saw it as clearly as if he were there. A woman was laughing. He stood on a wooden pier with grey boards and green sea showing through the gaps between them. The wind was blowing. A straw hat with a blue ribbon was tumbling along the boards, and a woman in a white dress was running after it, laughing so hard she had to stop and hold the rail. She shouted, Edmund! Edmund, get it! It was Brighton, in the summer of 1909, two years before she died.
Her name was Clara. She had been Hartley's wife.
John had never met her. Now he could remember her laugh as clearly as his own mother's voice. He had taken the memory out of Hartley's head, and it was in his own head now.
Time came back to normal speed.
Hartley stood by the hat stand with his hand out, blinking. A thin line of blood ran from his left nostril down over his lip. He touched it in surprise and looked at his fingers.
"Good Lord," he said. "I'm bleeding."
"It's the shock," said John. His own voice sounded far away to him. "From the overload. We both took a knock."
"Did we?" Hartley looked round at the burned coils and the cracked quartz as if he were seeing them for the first time. He no longer remembered the pencil, the stopwatch, or Pyle. "Good Lord. What a mess. We were lucky, very lucky." He held a handkerchief to his nose. "We'll clear it up tomorrow." He took his hat off the stand and put it on. At the door he stopped. A small, puzzled look crossed his face, like a man who has walked into a room to fetch something and can't remember what.
"Funny," he said. "I was thinking about Brighton just now. I haven't thought about Brighton in years." He shook his head. "Well. Melba. Goodnight, John."
"Goodnight, Professor."
The door shut. John heard Hartley's footsteps go up the stairs.
He stood alone in the smoky basement, with the laugh of a dead woman in his head.
* * *
Hartley's lab notebook lay open on the desk, where he had left it.
Every reading from the experiment was written there in Hartley's thin, spidery handwriting, right down to an ink blot where the pen had jerked at the moment of the flash. It had the coil measurements, the way the quartz was cut, and the batteries, bank by bank. It was everything a careful man would need to build the machine again and push it past the line.
John picked the notebook up and held it over the Bunsen burner by the sink. He turned on the gas tap. He struck a match.
He stood there with the match burning down towards his fingers and the notebook above the flame, and he couldn't do it.
The notebook held three years of Hartley's work and nine months of his own. These were the most important numbers anyone had ever written down, and you didn't burn numbers.
Somebody will find it.
The match burned his fingers. He shook it out. He put the notebook back in the desk drawer, under the blotter, where Hartley always kept it, and shut the drawer.
Somebody will find it, and run the machine past the line.
He turned off the gas.
* * *
John took his wallet out of his jacket. Behind the photograph of his mother was a letter he had carried for four years. It was a single sheet, folded small, and the creases had gone as soft as cloth. It was written in pencil, in his brother Tom's careless capital letters. 30th June 1916. Dear Johnny. Big show tomorrow, can't say more. Don't tell Mum but I'm not a bit scared, the guns have been at them a week and there can't be a German left alive...
The next morning, at half past seven, Tom had climbed out of his trench near La Boisselle and gone over the top into the Battle of the Somme. His body was never found.
John held the letter flat between his palms and shut his eyes. He thought: if the room could fall away to 2045, then it could fall away to 1916. He knew the date and the place, and he was holding something Tom had touched. He pushed, harder than before, trying to reach a trench in France on the last night of June 1916, the night before Tom died.
He hit a wall.
There was no other word for it. It felt like running full speed into a pane of glass in the dark. Something in his head went crack. Then he was on his knees on the stone floor. Blood was streaming from his nose onto the letter and onto his hands, his ears were ringing, and the room was spinning round him. Whatever this power was, it would not take him back to Tom.
He knelt there for a long time.
When he was able to, he folded the letter, blood and all, and put it back behind his mother's photograph. Then he reached up to grab the edge of the bench and pull himself to his feet. His hand closed on the first thing it touched. It was cold, round, and made of brass.
It was Hartley's astrolabe.
He looked at it. Under his bloody thumb, very small around the rim, were letters the engraver had cut into the brass. John had seen them a hundred times and never read them.
FACTA FLORENTIAE MDIII.
It was Latin: Made in Florence, 1503.
The brass was warm in his hand, and getting warmer. And slowly, gently, the way a boat pulls away from a quay, the basement floor began to slide away beneath him.