I stand under the showers at the edge of the pool, feeling the needles of water scratch their way down my back, then lower myself into the shallow end. The water is cold at first and my breath hitches a couple of times in response. There are two lifeguards on duty today. One is watching the baby pool where a few toddlers bounce in armbands and inflatable rings. When Charlie was a toddler I used to take him to the pool. All babies can swim, the memory of being in the womb still so fresh for them at that age. I took him only once, though, that was it. The thought of him underwater, mouth and nose blocked like that, I couldn’t keep going. My anxiety was too much, even then.

The other lifeguard – a man with a beard and yellow flip-flops – is sitting halfway along the length of the pool. He’s relaxed in his chair, not worried about anything. Trusting the swimmers to know what they are doing. The pool is about as full as I expected. Plenty of people doing lengths up and down. And there’s a wide space on the far side without lanes, where people can swim however they want. It’s best, though, I have learned, to stick near the lanes.

I check that my swimming cap is on tightly enough, then push off from the shallow end, ducking my head under the water. I start with breaststroke, swimming like a frog, letting my face dip under the water with each pull, melding into the flow of swimmers. To the lifeguard I’m just another woman in a black swimsuit and blue cap. Quite ordinary. After a few lengths the water doesn’t even feel cold any more. My goose-bumps have gone; my shuddering has stopped. It’s only that I am a little out of breath. I come to a pause at the deep end and hook my arms over the side, my heart running fast. I wait until my heart and breathing slow, then I slip under the lane ropes until I find a little space just off to the side. I look as if I’m just floating, taking a rest from doing my lengths.

I haven’t done this in a long time. I have been going too easy on myself.

I float in the water and breathe out slowly, letting each ounce of air out of my lungs. You can do this to calm down: expelling the carbon dioxide out of your system, letting that stale, anxious air release. You can do it for that.

I empty my lungs.

Then I sink myself under the water. Right down to the bottom of the pool.

It is very quiet and peaceful down here. I cross my legs, anklebones hard against the floor. My body is heavy with no air in it and I can sit, like a buddha, right on the bottom.