‘Can we move the bed to the other wall?’ I said. ‘Do you mind?’

We rearranged the room. He sat down on my desk chair, holding his back, and pulled a list from his pocket.

‘Your mother,’ he said, and shook his head. ‘Let’s see. Knee-brace?’

‘Yes.’

‘You’ve got all of your food.’

‘Yes.’

‘You’ve got your fancy dress things.’

We had been informed of various events in the first few weeks of term, and accompanying costume requirements. ‘I packed them,’ I said.

‘And you’re going to go?’

‘I’ll see how it goes, Dad. You can leave now.’

‘OK,’ he said. He wrapped me into his arms and kissed my forehead. ‘The welcome drinks,’ he said. ‘Promise me you’ll go to those, Lex.’

‘OK.’

The welcome drinks were tea and squash, which didn’t seem especially welcoming. A student from an older year, appointed to put us at ease, asked me a series of polite questions. Where was I from, what subject would I study, how had I spent the summer. Over his shoulder, a girl in a denim jacket had just said something to make the surrounding group laugh.

I excused myself. I would shower and prepare for the first week of lectures. That was a whole five days away. In the still of the strange new room, with the sounds of the reception stretching out across the gardens, it seemed like a very long time.

I was at my desk, reading about old laws, when somebody rapped at the door. I tiptoed to the keyhole and watched the girl in the denim jacket lean against the wall and fold her arms. She waited for one beat – two – and, bemused, turned away.

I opened the door.

‘Hello,’ she said. ‘This isn’t the greatest introduction, but I think that we share a bathroom.’ She stuck out a scrawny hand. She had vampiric dog teeth and crooked dimples, so each time you realized that she was good-looking, it surprised you.

‘The whole welcome thing,’ she said. ‘It’s a little awkward.’

Olivia was studying Economics. She had spent the last year as au pair to the children of an Australian oil executive, which had made her realize that money really, truly, genuinely doesn’t buy you happiness. One of the daughters faced her down on her very first day and told her that she would be gone within the week. ‘A year later,’ Olivia said, ‘she cried when I left. So that was a real triumph.’ She had already met the guy living below us, who was called Christopher and was studying architecture. His mother had sent him with brownies for the whole staircase, and he was stockpiling them under his bed, mortified. She looked past me to the little pile of belongings in the middle of my room, bunched together like there was safety in numbers.

‘Hey,’ she said. ‘Great duvet.’

Olivia met me in the champagne bar at Romilly Townhouse, and hugged me carefully. She wore aviators and a suit and a fine silk scarf, embroidered with ants.

We talked about Italy and the wedding, and the torta al testo which the couple served at midnight. ‘Truly,’ said Olivia, ‘the finest fucking thing that has ever been in my mouth.’ We talked about genealogy and genomics, in a broad sense; Devlin’s deal was confidential, and Olivia worked for a rabid investment outfit. ‘My dad tried it,’ Olivia said, ‘in a sort of start-of-retirement crisis. I think he found out that we were from Wales – where my grandparents live.’ We discussed the weather. We debated shopping in New York versus shopping in London. ‘But,’ Olivia said, ‘don’t you start to find the flattery grating?’

‘Your mother,’ Olivia said, as the fourth round of drinks was served. ‘Oh, Lex. I’m not going to pretend like I know what to say. But she brought you into this world.’ Olivia raised her glass. ‘So. Cheers to that.’

At the beginning, I would try to tell Olivia and Christopher all of the time. We would be walking to the college bar, or drinking in the gardens in the rusty October afternoons, and the words would rush up to my throat, tasting of bile.

They knew that I was adopted and that I was older than I should be. I wonder now about all of the other strange aberrations which they left unquestioned: the photograph of me and Evie on my bedside table, and my insistence on showering at inopportune moments, and my fortnightly journeys to London, where I walked through Fitzrovia, past the stern townhouses and the rainbow mews, to see Dr K. Did they consider whether they should ask me for an explanation? Did they debate exactly what the first question should be, in order to secure the highest returns?

If they ever did discuss my oddities, they concluded that they wouldn’t raise them with me. Term was passing, and my history had become like an acquaintance’s name: there was a point after which it became impossible to ask for it. I didn’t mention Mother and Father until our final year, and then, it was only because I had to.

It was late October, and the week of Halloween parties and dinners. Each evening, mist seeped in from the Fens, like autumn’s great party trick. Olivia and I recycled the previous year’s outfits, which had been highly acclaimed: we were the dead twins from The Shining, with pale blue dresses and just the right knee-length socks, which we had found in a back-to-school sale. We walked into the college bar hand in hand, looking serious, and Christopher turned to see us. A plastic knife was protruding from his skull.