‘Are you frightened of the dog?’ Sheanna said, throwing another stone in.

The sand was beer bottle-coloured. ‘What?’

‘Because that’s not in there. It’s in Lough ______.’

Matty thought blankly of the sheepdog up the road, its mindless, hysterical barking as it ran alongside the bike. ‘What dog?’

‘It’s called the Dob—’ She gave a pensive, assessing little hum, before shrugging. ‘The Dob-something. It lived in the water and it was really, really big, like a giant killer dog, and then it killed a girl, and then her husband got it back by killing it but when it died, it made a massive cry and its brother came. But the husband still killed it.’

Matty had pulled out a cigarette, lit it. A careful, shallow intake. ‘You read too many books.’

‘I don’t. You can’t read enough books. Books tell you facts.’ She said the last word with heavy relish. ‘Could you kill one?’

‘Maybe.’

‘I bet you could. Mermaids are dangerous. You know how everyone likes swans but actually they can break your arm?’

Matty drew on the cigarette. Just one more puff. ‘OK.’ It was a myth, that – they’d actually just hiss and flap their wings, but Sheanna didn’t need more facts.

‘So mermaids sit on rocks and comb their hair – because normally they have long hair – but only if they’re bored. They sing songs to sailors and the sailors can’t help themselves and they get sucked towards them and they’re all in love and then the mermaids eat them all up.’ She tipped her head up at the sudden sound coming from above them, to the right.

There was a growl, getting louder. A serrated sound in the sky, and an insect-like shape becoming larger. A helicopter, coming this way. Lowering.

Matty stood, quickly. Shit.

The lough became choppy. It was close enough to see the individual blades, and how they slowed as it landed by the shore, further down on the north side of the water, opposite them.

The helicopter door opened, and a soldier came out, followed by another, and another. They were holding guns, big ones.

They knew. Cormac had worked it out, and had radioed for back-up. They’d already been to the house. They were searching for Matty.

Sheanna had risen too, standing stock still as more soldiers got out, though she didn’t seem perturbed.

Ten soldiers, a small gap between each one, moved slowly along the road on the other side of the lough. They didn’t even look over.

‘They’re from the British Army,’ said Sheanna. ‘They come sometimes and walk down the road. Daddy says it’s best not to make a fuss.’ She sat down again.

Matty’s heart was throbbing, an insistent kick drum.

‘He says they’ll be gone soon. Did you hear about the dead man?’

Still frozen. ‘No.’

The helicopter rose, shunting backwards, the blades beginning to blur.