‘Is this about Mark Sullivan? Because you know he’s not actually conscious?’ The nurse sounds a bit exasperated, but nurses work twelve-hour shifts on this unit, so Joe’s not going to take it personally. Her name badge shows that she’s called Gloria Faithful, which feels like the perfect name for a nurse. ‘And your forensics guy left an hour ago,’ she adds.

‘Yeah, we know,’ Joe says, trying to sound grateful for her insight. ‘We just wanted to have a quick word with whoever’s in charge of Mark’s treatment. To get a likely prognosis, and check if or when we’ll be able to interview him.’

Gloria sighs. ‘Of course you do, sorry.’ Her face relaxes. ‘That’s Dr Rahim. She’s not here at the moment, but I can page her for you.’

‘Thanks. We’ll wait over there,’ Joe says, nodding towards a row of plastic chairs attached to the wall. Only one of them is occupied, and Jason guides them to the opposite end, conscious that visitors in a place like this don’t usually like police sitting too close. But this particular visitor keeps looking over at them.

‘Excuse me,’ she finally says. ‘Are you police officers?’

‘We’re with CID,’ Jason says in the polite voice he saves for members of the public.

‘Are you here about my boy?’

Joe pushes forward in his chair. ‘Who’s your boy?’ he asks gently.

‘Mark,’ she whispers. ‘Mark Sullivan. Someone strangled him. Why would they do that?’ Her face crumples and tears snake down her cheeks. She looks like the kind of mum who would remember tucking Mark in at night, Joe thinks.

‘You’re right, Mrs Sullivan, it is hard to understand why anyone would behave like that.’ He sighs, to prove that he’s still not immune to the horror of violent crime. ‘But DC Worthing and I are investigating what happened, and we will find out who did this to Mark.’

‘The nurse said he’d been sleeping rough, in an old shop. That he’d been doing drugs. But it doesn’t make any sense. Mark hates drugs. He was working, trying to get a job with one of those game designers. Why would someone want to kill him?’