Dominica arrives next to Tor, who is ahead of her at the water’s edge; Helga is coming now too from where she’s slung her things on the pile of their stuff by the groyne and Dominica waves to her. As usual, Helga’s dressed in her baggy blue swimming costume and retro swimming cap with a chin strap. She doesn’t give a monkeys about her saggy wrinkly thighs being on show, unlike Dominica, who is body-conscious even now.

They make an odd tribe, Dominica thinks, feeling a surge of affection for these unlikely friends. There are other swimming gangs she could have joined. The women from her old yoga class swim regularly, but Dominica wanted to swim without their concerned expressions. She’d happened to arrive at the beach at the same time as Helga and Tor a few times, and, before she knew it, they’d formed a flockette of their own.

Tor is in her late thirties and is wearing a Santa hat in honour of the occasion, her bright-purple hair, some of which has turned into dreadlocks, poking out from beneath it. Dominica puts her arm around Tor’s skinny tattooed shoulder and gives her an affectionate squeeze.

‘Fuuuuuuuuuuuuuuuuuuuuuuu,’ Tor mutters, as the bubbly surf gobbles at her toes. ‘It’s so c … c … cold.’

‘You OK, though?’ Dominica checks. She knows how much Tor has suffered with her diagnosis. It’s not fair on the poor kid. Dominica is always so impressed with her positive attitude and fortitude.

‘Yep,’ Tor says, the green diamanté in her nose glinting. ‘I’m glad I’m here. Lotte threatened to come, but she’s hungover.’

Dominica can imagine it. She’s met Lotte, Tor’s Dutch girlfriend, a few times and she’s quite a force of nature. She gets the impression that Tor likes coming to the beach for a bit of peace and quiet.

‘Come on,’ Helga declares, in her funny accent – half Danish, half cockney – marching past them. ‘Stop dallying, you two. Get in.’

In a couple of strides, Helga’s surrendering gracefully to the water, bending her knees, her shoulders sinking. She sighs, as if the sea is a lover welcoming her with a caress. She flips onto her back, her face radiant. She might be the other side of seventy, but, in the water, Helga looks about seven. Her feet pop up as she floats, her arms out to her sides like a quirky otter. Dominica sees her focusing on the bandstand and knows she’s working out which way the current is running from the pull on her body in the water. She’s a stickler for water safety.

Dominica walks forward with Tor, concentrating on making sure she doesn’t hold her breath, but it’s a shock nonetheless, bringing her fuzzy brain into focus, like a camera lens. The beach, the land, every thought she had up until just moments ago, is in the past. There’s only now. She’s tried meditation, but this works much better for calming her scrambled thoughts. A plunge in the sea pushes her mental reset button like nothing else.