‘I suppose you’ve had lots and lots of affairs in Cambridge,’ I told Erwin cheerily, as I stuck a snail with a pin in one of Cambridge’s determinedly French restaurants.

‘I seem,’ Irwin admitted with a small, modest smile, ‘to get on with the ladies.’

I picked up my empty snail shell and drank the herb-green juice. I had no idea if this was proper, but after months of wholesome, dull asylum died, I was greedy for butter.

I had called Doctor Nolan from a pay phone at the restaurant and asked for permission to stay overnight in Cambridge with Joan. Of course, I had no idea whether Irwin would invite me back to his apartment after dinner or not, but I thought his dismissal of the Slavic lady – another professor’s wife – looked promising.

I tipped back my head and poured down a glass of Nuits St George.

‘You do like wine,’ Irwin observed.

‘Only Nuits St George. I imagine him … with the dragon …’

Irwin reached for my hand.

I felt the first man I slept with must be intelligent, so I would respect him. Irwin was a full professor at twenty-six and had the pale, hairless skin of a boy genius. I also needed someone quite experienced to make up for my lack of it, and Irwin’s ladies reassured me on this head. Then, to be on the safe side, I wanted someone I didn’t know and wouldn’t go on knowing – a kind of impersonal, priestlike official, as in the tales of tribal rites.

By the end of the evening I had no doubts about Irwin whatsoever.