In front, the soggy grass that runs down to the dirty sand and slimy rocks of the shoreline. There should be an ice-cream van parked up, opposite the neat, newish houses that shelter beneath the perfect curve of the Humber Bridge. It’s not there today. He takes it as somehow symbolic – a bad omen.

Turns right. Sights home. A row of white fishermen’s cottages. A hanging basket outside his own – a splash of red against the chalky paleness of the terrace.

It takes a moment to make sense of what he is seeing. To turn the familiar scene from a memory into its new reality.

The door stands wide open. At the window of the neighbouring property, worried faces, peering out to see what is happening. Two doors down, another open door; a mother and son framed in the rectangle of light, faces angled towards the open mouth of Aector and Roisin’s home.

He glances past his own front door – down to the lifeboat station and the play park and the great mass of the woods beyond.

Sees her. Black hair. Barefoot. Dressing gown and pyjamas. Lilah, in her arms, holding on, ape-like. She’s running up the road towards home.

McAvoy screeches to a halt outside his own front door. Boots the door open and stumbles onto the pavement, running towards his wife; dirt on his knees, his palms – relief flooding him. She’s here. She’s safe. She’s well …

Twenty yards away her face comes into focus. He sees fear. Wild primal horror scored into the set of her eyes, the anguished line of her jaw.

Ten yards away, he sees his daughter’s crimson hand.

Five yards away, he thinks: Fin.

And then she is in his arms, dissolving in tears and rage, saying his name; the name of their son; and Lilah is holding up her gory palm, and the police officer within him is closing down, fading, becoming nought but air, as something else, something other, begins to take possession of his flesh.

‘No,’ he says, again and again and again. ‘No.’

She gasps, as if coming back to life. Takes his face in her hands, fingertips like teeth. ‘He took him!’ she screams, spit and snot popping on her lips. ‘Cromwell. Did this to Lilah …’

‘No …’

‘Daddy kept him alive. He escaped. He’s come back for us. I didn’t know. I swear, I didn’t know until a few weeks ago. I was so scared – so scared. And I couldn’t tell you. And I should … sweet Jesus, Aector, he came for Fin … he took Fin!’

McAvoy’s eyes darken. The clamour in his skull falls silent. For a moment, there is just the sound of the rain and the sensation of his wife and his daughter, pressing themselves damply against the great mass of his chest.

He scoops them up. Carries them into the house. Kicks the door shut behind him. The flowerpot swings on its hook. Catches the wind. Clatters free and plunges down.