The lake is silky smooth, lapping gently around the legs of the jetty. The knobbly planks beneath my toes are thick and warmed by the sun. Karl is on the bank, wriggling into his shorts under the towel Mutti is holding around him.

‘Careful, Hetty,’ Karl shouts. ‘The water’s deep out there.’

‘I’m just looking,’ I call back. ‘I want to see the big fish.’

I shuffle right to the very end and curl my toes around the edge. Crouching low, I peer into the water. I can’t see the bottom of the lake. Maybe there isn’t one. Perhaps the dark green water goes all the way down to the middle of the earth where savage monsters lurk, waiting.

Walter swims towards the jetty. He splashes his arms around then floats on his back, pale toes bobbing up out of the water. He pops up again, grinning at me, pushing his wet hair off his face. I wish I could have swimming lessons like Karl, then I too could glide like a fish, instead of splashing about in the shallows, stubbing my toes on jagged stones and slipping on slimy weed.

From my perch, I watch Walter swim further out into the lake. He disappears from sight, hidden by the solid wooden pillar of the jetty. I move to try to see him, but I lean too far and topple forward. My hands fly out, clawing at empty space, and I’m falling, down, down, down.