‘Shit.’ Every square centimetre of Will’s skin tingles, rough with goose pimples. He understands.

She smiles. ‘You’re with me, aren’t you?’

Much as he feels he should be, Will isn’t scared by these ideas. He’s just oddly satisfied, his brain fed to the brim with heady concepts. In fact, it seems impossible to be anything other than calm in the company of this woman.

‘So this messenger, this person in another plane, this ghost; they’re not necessarily dead.’

‘Not necessarily dead, yet,’ Ms Calloway corrects him. ‘They are dying, yes. But in a now that we have yet to reach.’

‘Jesus.’

‘Hypothetically speaking,’ she says, grinning this time.

Will wrestles out loud with the concept. ‘In the last throes of dying, someone’s consciousness could re-experience the months or weeks that led up to their dying moment. And while they are doing that, make contact with someone in the real world …’

‘Who’s to say for sure?’ Ms Calloway says.

‘So, when would this person actually be going to die?’ Will muses.

‘Only they could tell you that. That’s if they know themselves. You’d have to assume it to be in the fairly near future, I suppose.’

Will thinks of the desperation he could feel that night on the boat. He thinks of the pleading in that note taken by Nain. Time, as wonky as it may be, is very definitely running out.

‘What do they want?’ Will mumbles.

‘All you can do is listen and be there,’ Ms Calloway says. ‘What more can anyone do?’

Someone shuts off the lights in the corridor. The hoovers are silent now. A classroom door slams somewhere.

‘It’s late, Will,’ she says. ‘We need to go or they’ll lock us in.’

‘Thank you,’ he says. ‘I’ve really enjoyed this.’

‘Gosh, me too! We’ll pick it up again tomorrow, I’m sure.’

‘I’d like that.’

She hoists her scruffy bag on to her shoulder.

‘Hypothetically,’ Will mumbles one last time.

‘If it makes us feel better to say it, Will, then OK. Walk with me?’

Will grabs his own bag and follows her to the door, his hand hovering over the darkroom light switch.

‘So eerily quiet, isn’t it?’ Ms Calloway says, stopped a few steps ahead of him. ‘You could hear a pin drop.’

Will listens to the empty vastness of the building for a moment. There’s a gurgle of a drain, tree branches stroking a windowpane. He suddenly remembers processing that film with April after they’d been up all night, what they could hear in the dark: the church bells, the trains from miles away.

‘You OK, Will?’

The realization brings no fear. He’s ready for this. ‘You go ahead, Miss. I’m just going to finish something off.’

She nods, like she understands. ‘I’ll make sure the caretakers don’t lock you in.’