The woman with the bathing cap was there as usual, swimming back and forth across the cove, alternating between crawl and backstroke. She was always there before me, no matter how early I arrived. On the first morning we’d smiled at one another in passing, and after that we’d got into the habit of saying hi, and yesterday she’d emerged, dripping, as I was about to leave, and called out—as if we knew one another well—“See you!” People never did that back home at the public pool. I would miss her when I was gone. I’d miss my early morning scramble down the cliff path. I’d miss the space, and the quiet, and the cool, clean smell of stones and salty water.

I reached the foot of the cliff and undressed next to my usual rock. I wouldn’t have wanted to swim from the main beach in Bligh, watched over by all those Victorian hotels and flats, but I liked this little bay beneath the gardens of Byrne Hall. It was completely hidden from view of the town, and I’d have thought it secret if it weren’t for the woman in the swim cap. She was taller and darker than Stella but sometimes, as I was scrambling down the cliff path, I narrowed my eyes and imagined that I’d surprised my sister swimming in the bay. All I had to do was brave the cold water to reach her and bring her back to shore.

I winced my way across the shingle and waded in, up to my knees. The waves were like icy tongues licking at my thighs and I half decided—as usual—that I wouldn’t swim after all; I’d just paddle about and get out. I thought of Stella and our childhood holidays in Cromer, when we’d yelp and splash and go right under, holding our noses, on the count of three.

The woman powered past, her mouth twisting out of the water to catch at the air. She was a proper swimmer, as sleek as a seal in her black costume. I bet she timed herself, kept a tally of lengths, and mildly despised me, with my goose bumps and my green polka-dot costume and my dithering.

“One . . .” That was Stella’s voice, whispering in my ear.

“Two . . . three . . .” I hesitated, even after the three, but I plunged forward, pushing my feet off the sand and taking flight. The first split-second was painful, before the water loosed its icy grip, and I was off. It was always the same. Once I was in, I couldn’t get enough of it; I had to dunk my head under and fill my fists with sand from the floor, roll onto my back, and try not to laugh within earshot of the woman.