I remember reading to her under the tree there and then reuniting with her after we split up. In a way we grew together in this place, the trees and us, sapling to oak. Once, I took her blindfolded across the park in the middle of summer. Her birthday was in December but she hated the winter. That year we had decided to celebrate it in August when the sun was shining so she could have a birthday photograph in the sun. I had hidden a picnic of sandwiches and champagne by some trees earlier in the morning and then surprised her by having Seb and Nina turn up.

‘Oh, my God. Xander!’

‘Happy not birthday, Mabe.’

I remember another time, a few weeks after the incident with Ariel. I had tried to convince myself and her that I wasn’t jealous, or more accurately that I no longer was, and that I understood my jealousy was a violation of her trust. I walked her casually through the park – a small box burning a hole in my pocket. There was no reason to be nervous, not really – it was just a peace offering but it had the quality of a proposal. Perhaps it was, in a way. We ambled hand in hand towards the boating pond but skirted the edge. There had been a time when Grace pulled me towards boats but eventually she gave up when I’d resisted enough times. I hadn’t wanted to dilute the day that we’d taken the boat at midnight. To get on one of these pond boats seemed like a violation of that memory. We passed the parked green pedalos and were a few paces on when I turned her back.

‘C’mon then, Mabe,’ I said. ‘Just this once.’

She raised her eyebrows in surprise and then lit up. After picking her way artfully on to the boat, she sat grinning on the bench seat, while I paid. The sun was shining hard so that by the time I had manoeuvred us out of the mooring, I was already flushed through with heat. I rested a little then as the boat glided under its own momentum. I produced the box. Heart beating.

‘It’s a conch,’ I said as she lifted out the tiny gold shell suspended on a gold chain. ‘Fibonacci and all that,’ I said, trying to sound careless about it.

She put it straight on and beamed at me as I breathed out relief.

She wore it then, every day.

Until she didn’t.