—So I can’t step on a butterfly and accidentally change the future?

No! It’s pretty deev if you think about it. You were always meant to go back in time. In a way, you already have. And once you’re done, you’ll return to the same future you left. Simple!

He fell backwards onto the carpet, drowning in waves of relief. The future he’d read about was safe. Nothing could change it.

When his heart had slowed its pounding, he got up. He paced to the mirror and stared at his reflection: flushed, wide-eyed, like he had woken up from a dream to find it was still happening. He held the book up next to his face, mirroring the image of the poet. He turned his head to match the angle, arms awkwardly open to embrace an invisible Diana. The resemblance wasn’t perfect: aside from the obvious problem of the missing muse, there was something in the depths of the poet’s eyes that he couldn’t replicate, no matter how he squinted. Notthe poet, he reminded himself. “Joseph Greene,” he said aloud, imbuing his name with an English-accented gravitas that matched the serif font on the book’s cover.

Like tilting a hologram, his perspective shifted. He saw himself from the outside, and what he saw was hilarious. He burst out laughing, falling onto his bed, pressing the book to his face. “It’s fucking real,” he said into the pages. “It’s going to happen.” He laughed and laughed, a joyous convulsion that took all the coiled-spring energy the poems had wound into him and flung it back out into the world.

When the laughter was over, he sat up. He took in the familiardetritus of his room: the Highland cow, the bus, and the penguin scattered across the floor; the philosophy books sitting unread on the windowsill; his threadbare coat, hanging where he had flung it over the back of his chair. Something pink was sticking out of the pocket.

It didn’t feel like a decision. And, after all, it wasn’t.Anything you do in the past has already happened.He got up, his body moving without his direction, and spread the flyer out on his desk. Love Poems for Tomorrow. He had imagined the audience in the ADC Theatre, sitting rapt as they witnessed the beginning of his future. He had given that vision up because he hadn’t experienced a love worth writing about. But his future self didn’t have that problem. He had fallen in love and risen out of it better, more interesting, ready to write the poems he was always meant to write.

He opened the book again. He leafed through, considering each poem, finally settling on one about a kiss, exuberant without being juvenile, sensual without being embarrassing. He opened his laptop, minimised the MSN Messenger window he mainly used for asking Rob to make him tea, and brought up his university webmail. In the body of a new email, he typed out the poem, word by word, constantly checking to make sure his imperfect younger self hadn’t introduced an error. It was a strange, meditative process, flicking back and forth between the printed page of the future and the glowing screen of right now. He felt the words passing through him, like he was a conduit for something greater, taking dictation not from the muse but from a better version of himself.

He read it through and nodded in satisfaction. In the “To” field, he typed the email address on the flyer. As he hovered over the Send button, a tremor of doubt assailed him. He tried to reassure himself. They were his poems. The fact that he hadn’t technically written them yet was beside the point. But he couldn’t shake the idea that he was doing something wrong, if not morally, then metaphysically. His gaze flicked to the philosophy books on the windowsill. Maybe if he had actually read them, he would have a better idea of the implications of what he was about to do.

The living room door banged, announcing Rob. “Greeney, what have I said about hijacking the punt when I have paying customers? I had to tell my manager you were a tragic wild boy raised by swans or she would have sacked me.” His footsteps came closer. “What are you doing back there? Are you actually working? This I have to see.”

Joe panicked, closed his eyes, and clicked Send.

Chapter Four

He shut the laptop and lunged to hide the book under his pillow. By the time Rob peeked around the door, he was poring over a philosophy textbook in a way that almost certainly looked suspicious. “Sorry,” he said absently.

“Ah, no harm done. Only one person complained. The rest of them lapped it up. I spun it into a whole story about how you were the ghost of a student who drowned himself after failing his exams.”

“Hey,” Joe protested weakly.

“It was very moving. Especially the part where I mimed your floating corpse.” Rob paused, looking at him closely. “Yes. That’s exactly the expression. Uncanny.”

He needed to get his face under control. He closed the textbook and spun round in his chair. “For your information, I’m going to get a 2:1.” Saying it aloud brought home what it meant: he no longer had to worry about failing. The crushing pressure lifted from his chest, finally letting him breathe.

“Great news,” said Rob. “Happy for you. Is that what you’re wearing for Halloween Formal?”

He looked down at himself. “No. But that’s not till this evening.”

Rob indicated the darkness outside. “Through the magic of time travel, this evening is now. So come on, get spooky. We haveto be there in five minutes.” He tapped the door frame and disappeared into his own bedroom.

Joe stared out at the fingernail crescent moon hanging over the battlements. Hours had passed in the present while he had been wandering the pages of the future. He got changed into his costume, but his heart wasn’t in it. He felt like he was his older self, playacting at being a student again.

When he emerged, Rob was baffled. “Why do you have a toy train hanging off your jumper?”

He indicated the bridge motif knitted into the jumper, and the deliberate rip he’d made down the middle. “I’m the Tay Bridge Disaster.”

Rob made a face. “Isn’t that a bit tasteless?”

Plucking at the jumper for emphasis, he explained, “‘The Tay Bridge Disaster.’ By William Topaz McGonagall.” He searched unsuccessfully for recognition in Rob’s eyes. “Worst poem ever written? Rhymes ‘buttresses’ with ‘confesses’?”

Rob shook his head. “Greeney, you’re supposed to wear a costume someone other than you would have a chance in hell of recognising.”

Joe looked Rob up and down. He was dressed as usual for Formal, in a shirt and black jacket under his gown. “What about you? Who are you supposed to be?”

“I’m Future Rob,” he said, leading the way down the stairs. “Rob from the future.”

Joe stared at his roommate. Had he sneaked a look at the book while his back was turned? Trying to be casual, he said, “You’re still going to be wearing your undergraduate gown when you’re sixty?”

“Who says I’m sixty?”