And yet Cathy knows they are all expecting sniffer dogs and armed police and a last-minute announcement over the tannoy on the plane.

Lydia has been quiet. She’s now browsing the perfumes in duty free, but in the manner of somebody who isn’t really looking. Cathy is privately worried. Lydia doesn’t miss a trick. And it is impossible to act normally when you have been complicit in the burying of a body seventy-two hours earlier.

‘Giant Toblerone?’ Joe says, walking over to Cathy as he holds one up. Cathy looks at him, her complicated, tender, brittle brother. How can he act so normally? She’s got to raise it with him.

Together, they drift into the make-up section. Their eyes are reflected all around them in a hundred mirrors, bouncing off the bright, white spotlights up ahead.

‘Joe,’ she says.

He looks at her wordlessly.

‘Why is your name on the document Will had?’

‘What?’ Joe says. His mouth falls open in shock, his eyes squint up, as though he is studying something very close up that he can’t quite make out.

‘Why is your name on the warrant?’

‘Not here,’ Joe says, and Cathy feels a flash of relief, of hope that he might explain. Cathy leads Joe out of the shop, away from the multiple refracting fairground mirrors and the CCTV.

They leave through one of the automatic doors that fronts the runway, leading to a smoking area. A plane, just taken off, banks and loops back on itself as they watch it.

‘What are you talking about?’ he says.

‘Your name is on that warrant, Joe. Right at the bottom. Along a rip.’

‘What?’ he says.

‘You don’t know why it says Joseph Plant?’

‘I have no idea,’ Joe says. He waits a beat, then says, ‘What kind of a conversation is this?’ It’s become a family phrase, that sentence. Frannie started it. She’d been through a phase of drinking, smoking, skipping school. She used to try to control her tellings-off, like she was a CEO or something. ‘What kind of a conversation is this?’ she’d said, bold as anything, standing in their hallway, an hour past her curfew, in a skimpy dress, smelling of cigarettes. Joe had caught Cathy’s gaze and they’d both dissolved into giggles, much to their parents’ annoyance.

‘I don’t know,’ Cathy says quietly.

They walk further outside. A gust of air carries the smell of hot engines and petrol on it. It whips Cathy’s hair around her face. She pushes it impatiently behind her ears and carefully hands Joe her phone, keeping it angled close to their bodies.

Joe stares at the phone cradled in his hands. His body is bent over it, his head dropped downwards. He stands with his weight on one leg, the toe of the other foot resting behind him. He looks both curious and casual. Totally natural, Cathy thinks as she assesses him.

‘I have no idea,’ Joe says eventually, his tone mystified. If he’s lying, he’s convinced her.