Tim couldn’t remember the exact moment when he realised his father wasn’t human. It was certainly a long time before the final cat, when his dad got sick, but looking back he couldn’t pin down a specific moment of realisation. Probably it just came as a gradual understanding, like so many things do at that age.

Either way, whenever his father killed a cat Tim was always careful to watch his face. He soon realised that the subtle change he’d seen in their back garden wasn’t a one-off; in the moments building up to the kill and straight after it Mr Stevens’ face would slacken and droop as though his skin had started to melt; his mouth would pucker open and his eyes would change from brown to yellow. It only ever lasted 10 seconds at most, though, and then the change would stop. The cat would be dead and his father’s face would look normal again.

Tim used to pray that he’d never, ever see what his father looked like if the change went all the way through. And up until the last cat they killed – just before his father became ill and then disappeared for the next three years – Tim didn’t have to.

Now, standing on the moor next to his rucksack in the wind and the light drizzle, Tim could see it all too clearly in his mind. His father’s face drooping down and the mouth hanging open wider and wider; his yellow eyes lengthening and squeezing out at the sides, like the magnified eyes of some nightmare insect; his jaw stretching open to an impossible size, opening on a dark void ringed by multiple rows of tiny white teeth–

‘He’s not there!’

Tim was snapped out of his unpleasant daydream by the sound of a voice. Seconds later Matt and Tramper came bursting back into the clearing, their faces red and their eyes wide. James bent down and put his hands on his knees, breathing heavily, but Matt jogged over to Mr Stevens, who was busy adjusting the straps of his rucksack.

‘He’s not there,’ Matt panted. He stopped a few feet away from Tim’s dad and pulled in a deep breath.

‘What do you mean he’s not there?’ Mr Stevens’ face was a mask of surprised concern.

‘We checked all down the path, both sides, and we were shouting his name. It’s just like with Gary, he’s gone, he’s fucking disappeared.’

Tim flinched and glanced at his father, but Mr Stevens was frowning and looking at his watch. ‘There’s a storm due to come in later,’ he muttered. He glanced from Matt to James, then back to Matt again. ‘Are you sure you checked properly? He can’t just have vanished, for goodness’ sake.’