‘I lost my temper when I knew I wasn’t going to get any answers from him. I cleaned up straight away and explained to the nurse that there’d been an accident.’

‘What about the smashed glass in the patio door?’

‘I kicked it in frustration, just with the tip of my boot so there won’t be a print. There was a stress mark in the glass but it didn’t break. I wasn’t responsible for that,’ Callanach explained.

Ava sighed. ‘Which just leaves the issue of you having used your badge to gain access. What’s your explanation for that going to be?’

Callanach ran a hand through his hair. ‘The bigger problem might be the DNA.’ He smiled at her. ‘Depending on how carefully the lab checks the two samples, mine and his.’

‘I don’t understand,’ Ava said.

‘My mother never told my father about the rape and so that he didn’t suspect anything, she continued having intimate relations with him as normal. The following month it became clear that she was pregnant.’

Ava took a few seconds to process the relevance. Her hand flew to her mouth.

‘Oh no. Luc, I’m so sorry. He can’t be …’

‘Actually, there’s a one in three chance that he is,’ Callanach said. ‘I don’t have anything left of my father’s to check the DNA, so all I have is a process of deduction. That’s why I was there. I took a hair from his head and sent it away for testing.’

‘But if he’s your father, your DNA might look oddly similar to his when the Scenes of Crime forensics tests come back.’

‘Yeah,’ Callanach said.

‘Which would easily be motive enough to put the case before a jury, with the rest of the evidence. Fuck.’

‘Uh huh,’ Callanach agreed.

‘Fuck, fuck, fuck,’ Ava finished. ‘But that’s only a one in three chance, like you said. Even if he does turn out to be …’ – she chose not to say the actual words – ‘the lab may not put two and two together from the sets of DNA, especially if they’re already expecting to find yours on the corpse, so they won’t be doing anything more than double-checking it against the sample of yours that’s already on the database for exclusion.’

‘Ava, whatever you’re thinking, you have to stop. If we try to cover this up there’ll be a disaster. Right now I have nothing to hide.’

‘Are you kidding? Nothing to hide? You went to see a man who ended up dead, who at the very least conspired to rape your mother and who might be your father. What the hell do you think is going to happen if this goes to court? Were you angry? They’ll point at the broken vase. Were you trying to conceal your identity? They’ll say that’s why you didn’t sign the visitors’ book …’