This time around, too, there were signs of the differences in their natures. One was revealed at the dinner at high table. Danny was being feted by the faculty, who held a dinner to toast his plans for the revamped centre. It was hosted by the chair of the zoology department, a fellow of Halsbury College. Rose arrived at the college a half-step behind Danny and the sprightly professor.

‘Evening, mate,’ Danny said to the porter as he entered. Very familiar, very likeable. As if he was Brian bloody Cox.

Rose stopped a moment longer. A fixture in the college lodge, the porter knew everyone’s comings and goings. ‘Hello, Red,’ she said, greeting his elderly staffy, who wore a jaunty red bandana for a collar.

‘Hello, Mrs Frank,’ the porter said. He didn’t know Rose’s name, but had seen her out walking her dog. She was touched that he recognised her in a different context. She didn’t normally come to this college, which was very big and grand, one of the grandest in Oxford. ‘And how is Frank himself?’

‘Oh, he’s exceptionally well.’

Patting Red, she noticed just how old he was, and the thought of how his death would devastate his owner made her feel suddenly like crying. Not normally prone to tears, she wondered if she was starting her period. Walking at the heels of two other dinner guests as she entered the hall, she realised they were talking about the porter.

‘It was his son who died. Doing the rounds.’

‘Was it? Christ, I didn’t know.’

‘Terrible business.’

Inside, she sought Danny’s eyes. She was rattled now, and she wanted to know whether their secret was having the same effect on him, making him feel permeable and exposed. If so, he showed no sign of it.

At dinner he was in good form, conversing easily with the dons at the long table. It was the whole Harry Potter extravaganza: little lamps on the table, vaulted stonework high above. Sitting diagonally opposite Rose, he didn’t draw her in or introduce her. He seemed not to be aware of her turmoil.

(What is it like to be Rose Dawson?

‘We must consider whether any method will permit us to extrapolate the inner life of a Rose Dawson from our own case, and if not, what alternative methods there may be for understanding the notion. Our own experience provides the basic material for our imagination, whose range is therefore limited.’)