She looked at him sideways. “But if I was always meant to help you, then it’s not like I had any choice.”

“Then I don’t have any choice either.”

She smiled, brief and incandescent. For a moment, they just looked at each other. Then she coughed and stood up. “I should go.”

“Threshold?”

“Threshold.” She touchedMeant to Bewhere it lay on his desk. “Good luck with her tomorrow. Not that you’ll need it, obviously.”

A thought struck him. He opened the book to the page with the photographs. “What if I show her?”

She looked at him like he had gone insane. “The book of all your future poems about her?”

“No!” He pointed at the picture of her mum with Diana.

She shook her head. “Too risky.”

“What’s the risk? We’re not sticking her face up all over town. We’re showing it to one person, who clearly already knows her.” He looked up at her earnestly. “It’s our best lead. We’d be idiots not to use it. If they’re still friends, Diana can lead us right to her. If not, we can still narrow down which college she’s at.”

He saw her waver, the conviction that had led her this far softening under his words. For an uncertain moment, he wondered if he was doing the right thing. “Fine,” she said. “Ask if she knows her. But don’t tell her why you’re asking.”

He nodded. “I’ll be careful.”

She tapped the door frame, ducked her head, and left.

“So,” said Rob, waggling his eyebrows as Joe shut the living room door. “I’m assuming that was Diana?”

Joe stared at his friend, completely thrown. “What?”

“Diana,” Rob said slowly. “The girl you wrote the poem about.”

“No. No, that was...” He stared at the door, wondering how Rob could have got the wrong idea so completely. “That’s Esi. She’s—we’re...” He didn’t know how to describe what they were. Friends? Acquaintances? Reluctant coconspirators? “She’s not Diana.”

“Okay,” said Rob, in the voice that meantWhatever you say, Greeney. “Well, she makes a mean throwing star.” He flicked it in Joe’s direction.

In an uncharacteristic display of reflexes, he caught it. He turned it in his hands, thinking about Esi as she made it, her look of intent concentration. The way she felt unrooted, in his world but not of it. “Don’t get too attached,” he said, wondering who he was talking to. “She’s not sticking around.”

The next morning, he stood outside the gate of Whewell’s Court, agonising over the most poetic way to tell Diana he was here. Finally, he settled for:

Here

Across the street, the Great Gate of Trinity was thronged with tourist crowds. Among them was a group of time travellers who had followed him from college. Vera was corralling them together, ushering them back towards King’s. He was wondering why when he remembered the terms and conditions.Time travellers may not follow the target into any private premises.Shame, that they wouldn’tget to witness his historic first rehearsal with Diana. Maybe later, he could arrange a special outdoor performance just for them.

The gate buzzed open. He slipped into the sudden quiet of the court, then climbed the staircase labelledFand knocked on the fifth door.

As he waited, a painting on the neighbouring door caught his eye. A forest of golden lines grew sideways through shades of black, varied and subtle as a monochrome rainbow. He wasn’t sure what the picture was meant to be. The longer he looked at it, the more possibilities he saw: a sideways lightning strike; a reef of branching coral in a dark ocean; hundreds and hundreds of paths, branching out from one initial step.

Before he could work it out, the door in front of him opened. Diana, in a crisp white blouse and fitted skirt, her eyes cool and assessing. “Train Boy!”

He winced. “Am I ever going to live that down?”

“That depends. Can you impress me enough to make me forget?”

Her attention made him feel like the most important person in the universe. What should he say?Yeswould be too arrogant,notoo self-deprecating. He searched for a third response that would strike the perfect balance and also make her laugh, but too much time had passed, and he had to settle for mysterious silence.

“Well?” She was holding the door open. “Are you coming in?”

He stepped inside. He had hoped the room would impart something of her essence, but he just saw a mess: books in tottering piles, clothes in silky heaps, copies ofVogue Parisspilling out of the blocked-up fireplace. In defiance of college regulations, the walls were covered with photographs from ADC shows and clippings from the theatre pages ofVarsity. The muffled sound of a woman singing drifted through the wall. He was about to jokingly ask her if it was the muse when she said, “I’d like to start by hearing you read the poem.”