It didn’t start with the river boy. It started, as so many things started, with Grandpa, and with swimming. It was only later, when she came to think things over, that she realised that in a strange way the river boy had been part of her all along, like the figment of a dream.

And the dream was her life.

Half-past nine in the morning and the pool was crowded already. That was the down-side to summer holidays, especially hot ones like this, but she knew she shouldn’t grumble: she’d been here since six thirty, together with the usual hard-core of serious swimmers, and she’d managed a leisurely four miles without interruption.

But she did grumble; the mere sight of all these people flopping in like lemmings made her want to shout with frustration. She wasn’t ready to stop yet, not by a long way. She had energy left and she wanted to use it.

She stuck to her lane, doggedly ploughing length after length, trying to ignore the splash of other swimmers. Sometimes she’d found that if she just forced herself to keep on swimming, the other users of the pool seemed by some collective telepathy to accept that space as hers, and leave it to her. But that wouldn’t work today: they seemed to be jumping in by the score. Another quarter of an hour and it would be unbearable.

She locked into her stroke and drove herself on, her breath beating its practised rhythm in time with her strokes, as even as the chime of a clock. In for a gulp of oxygen, her mouth twisted upwards to snap its life from the air, then face down again and the long exhalation to a slow, steady count, bubbles teasing her lips like tiny fish.

She loved this rhythm; she needed it. It kept her thoughts on track when they started to wander. Sometimes, when things were going well and she was feeling secure in herself and had something pleasant to think about, she was happy to let them wander; but if she was tiring or feeling vulnerable or worrying about Grandpa again, she focused on that rhythm and it settled her, sometimes even when she wasn’t swimming.

But she was always swimming. She needed to swim. To be deprived of swimming would be like a perverse kind of drowning. She loved the sensation of power and speed, the feeling of glistening in a bed of foam, even the strange isolation of mind in this watery cocoon. Distance swimming was as much about will as about technique; and she knew she was strong in both. All she needed now, to set that will alight, was a big swimming challenge; something to test herself against. Something she could one day be proud of.

She heard Grandpa’s voice calling her.

‘Keep going, Jess!’

She glanced up at him as she flashed by, and smiled to herself. She knew what ‘keep going’ meant. Dear old Grandpa: he’d only been here twenty minutes and he was bored already. He ought to know by now that he could never fool her, of all people. His concentration span had always been short, except when he was painting, and his temper shorter still. Yet for some reason he always liked to come and watch her swimming.

She reached the far end of the pool, turned and kicked off the wall, and looked for Grandpa again. He’d wandered round to the shallow end and was standing there, watching some children. He was ready to go; but maybe she could squeeze in a couple more lengths to finish off. She plunged down towards him, feeling for some reason slightly apprehensive. The children in the shallow end blocked her lane but they broke apart as she approached and she slipped in between them, wondering whether she should stop.

Grandpa called out again.

‘Everything’s fine, Jess. Keep going.’

She kicked off the wall and headed back down the pool, suddenly desperately uneasy. Something was wrong but she couldn’t work out what it was. His words rang in her head: everything’s fine, everything’s fine. And yet there was something in the very contrariness of Grandpa that told her he was trying to conceal something. He was such a stubborn, prickly old man, he would always say everything was fine.

Especially when it wasn’t.

She broke out of her stroke and stopped, treading water, and searched for Grandpa. There he was, still standing by the shallow end, watching the children. He looked all right; no different from before. Just bored. Perhaps she was imagining all this. He saw her and raised a hand to wave.

Then, to her horror, clutched it over his heart and crashed into the pool.