Fry stood up. ‘I understand. Well, until we speak again, Mr Mullen, I’d like you to see if you can remember who else you spoke to that night at the Forester’s Arms and at the Broken Wheel, and the names of everyone who was there that you knew.’

‘What?’

‘Well, think about it, sir. If that fire was started deliberately, it might have been done by someone who knew that you’d be out of the house at the time. Someone who’d seen you partying at the Broken Wheel with your friend Jed, perhaps.’

Mullen nodded silently.

‘Still can’t think of anyone?’

‘No.’

‘Well, we’ll keep making enquiries.’

‘You’ve talked to Henry and Moira as well, haven’t you?’

‘Yes, I visited them the day before yesterday.’

‘Why did you have to bother them? They’re devastated about Lindsay and the children. We all are.’

‘There might be some detail that Mr and Mrs Lowther have noticed. A person they’ve seen near your house, for example.’

Mullen’s expression darkened further. ‘You’re not letting go of this idea that the fire was started deliberately?’

‘No, we’re not letting go of it, Mr Mullen,’ said Fry. ‘Is there some reason that you think we should?’

‘I just don’t see how it’s possible.’

‘We’ll know that better when we get the results of the forensic examination.’

His shoulders sagged at the mention of forensics. Sometimes, the word seemed to carry a symbolic power, as if it was a scientific magic that human beings were helpless to challenge. And perhaps that was right. Forensic evidence could kick-start a process that was impossible to stop until the criminal justice juggernaut had crushed everyone in its way.

‘Leave me alone,’ he said. ‘Leave us alone. Someone has got to look after Luanne.’

‘I thought you were a bit rough on Mr Mullen,’ said Cooper as they left the hospital and walked to the car park.

‘Yes, I was. And wouldn’t you have expected him to complain a bit more?’

‘But if he had complained more, then you’d be saying he protested too much, and that was a sure sign of guilt.’

Fry laughed. ‘Look, you know the husband is by far the likeliest candidate in a case like this.’

‘Statistically speaking, yes.’

‘So we have to look at him thoroughly. There shouldn’t be any question of letting him get away with conflicting statements, just because he’s supposed to be the grieving husband.’

‘Conflicting statements?’

‘Yes, like when “out with mates” suddenly becomes just one mate when he’s pressed. It sounds to me as if good old Jed is the only mate Mr Mullen actually had lined up for an alibi. He had to change his story when he was asked for names. Not enough attention to detail, you see.’

‘Diane, you’ve got him well and truly in the frame already, haven’t you?’