I wake up when I feel water drip onto my belly. Beau is standing over me, a hand outstretched.

‘I think this one has an animal inside,’ he says, kneeling down beside me, holding a striped cone shell on his open palm. He watches the shell intently but the small creature is not tricked into peeking out. ‘Can you mind it for me?’

‘Sure,’ I say. ‘Maybe it’ll pop its head out later. When it thinks we’re not looking.’ I prop myself up on my elbows. ‘Where’s everyone else?’

He points to Sarah, plopped down on the sand, her back to the sea, digging, and tells me that Mark took the twins back to the tents because they were hungry again. ‘Who could’ve predicted that?’ I say. And we share a smile.

‘Are you going to swim?’ he asks.

‘Sure, yes. You go ahead. I’ll join you in a sec.’

I watch him walk down to the water, skinny, arms like twigs, knock-kneed but striding. I feel a stab in my stomach at how vulnerable he is, and know that it’s our job now – mine and Mark’s – to keep this boy safe and happy. I fold the corner of my towel over Beau’s shell. The wind has picked up and I worry it might get blown away.

I follow Beau out into the sea, ploughing forward as the water deepens, holding my balance against the current, which is stronger than I’d expected. I look out at the inlet, the boundless expanse of sea, out to where the whitecaps are spaced far apart. I rise and fall on the ocean’s breath, lifted slowly then lowered.

There is nothing but ocean around us, water so clear the sunlight marbles my thighs and I can see the red nail polish on my toes. The swell raises my arms up. ‘Wave,’ Beau calls. He points at the water rising behind him. He’s excited, not scared. I give him a thumbs-up. He disappears under the churning water to come up on the other side. I marvel at how he knew to do that. He flicks wet hair from his face and we grin at one another. I turn and watch the wave melt to a spill as it touches the beach.

But something isn’t right. I feel sudden panic as Beau grows smaller right before my eyes. This current is dangerously strong. I should’ve noticed the rip. I call out to him, trying to hide the worry in my voice. He’s moving away from me quickly. There are no whitecaps where he is now. The water is darker. ‘Swim to the sand,’ I yell, but he’s not in control of where he’s going.

‘Sarah, Sarah.’ I want her to run for Mark, but she can’t hear me. We’re already too far out.

I tread water in my safe spot outside the rip while I figure out how I can get to Beau. There’s no easy way. I need to swim a large arc around the edge of the current then cut into it and allow it to pull me to him. Summoning my muscles and resolve, I remind myself I’m good at this, that the water was once my second home. ‘I’m coming,’ I shout to him.