I know I have to pull myself together. I’m full of anxiety, guilt, suspicion, and I cannot let myself get like that again. If someone doesn’t want me asking questions about Sarah, then I’ll stop. It seems I should never have tried in the first place, because look at the toll it’s taking on me.

All of my old anxieties re-triggered.

But I know something that will help. Something that will help me put all of this behind me. I go into my bedroom and pack a bag. I have to dig in the back of my wardrobe to find the flimsy black costume, but eventually I pull it out, and find an old towel in the bathroom to take as well. This idea isn’t on any of the pages in my bedside drawer. It’s another kind of strategy, one I discovered all by myself. Now it feels like returning to an old friend.

It is as cold as ever as I walk down the hill to the centre of Brixton. The light is so clear, it makes the edges of everything look razor sharp. As if they would cut me if I held a finger up to them. I pass under the rail bridge and turn right along the pedestrianized road where there are a few stalls selling household goods. A row of checked tea towels flap in the wind, a whip-crack of a sound.

Inside the big brown building, the smell is exactly the same as ever: chlorine. It’s well heated inside, warm after the chill of my flat. It’s an open session and it’s during the school day so there won’t be lots of kids, but Brixton Pool is busy whatever time I’ve come. I am sure today it will be busy enough.

The changing rooms need refurbishing and the latch on the cubicle door I choose isn’t working properly, but it is all so familiar that I don’t mind. I pull off my layers – so many layers in this cold weather – and pull on my swimming costume and fit my swimming cap over my head. My hair is that much longer than when I last came that it’s hard to fit it all under the tight rubber now. I have lost weight too since I last came here, it’s quite obvious now: my hipbones jut through the Lycra.