‘Holy shit,’ Ava said. She tapped the desk and stared blankly at the wall. ‘Okay, it’s not that bad. No one’s going to believe you were involved in a murder. You just need to present your reasons for being there and explain the sequence of events. They don’t have any sort of motive for you to have hurt him and that’s the most compelling evidence in cases like this. It’s probably someone who has day-to-day contact with him.’

‘You think it was a staff member who killed him?’ Callanach asked.

‘That would normally be the first consideration,’ Ava said. ‘It’s hard work looking after dementia patients and carers have been known to break down, either from the stress of the job or from a desire to end the suffering quickly. We’ll be checking the family too, of course …’ Her voice trailed off.

‘There’s a but,’ Callanach commented.

‘Actually, the “but” is broken glass in the lower section of a patio door. Scenes of Crime think the glass was broken potentially to allow an intruder to reach up inside and unlock the door. It explains why no one apart from you or staff members was seen in the corridors during the evening. That’s extremely helpful to you. Why risk being identified by the staff and then breaking the door? It makes no sense. Either that or it’s genius deflection.’ She gave a small smile.

‘Ava …’ Callanach whispered.

There was a knock at her door.

‘Come in,’ she called brusquely.

Pax Graham entered, keys in hand. ‘Oh,’ he said, looking from Ava to Callanach. ‘Am I interrupting?’

‘Not at all,’ Ava replied, back to businesslike. ‘I was just asking Callanach about the nursing home. He was there visiting Mr Jenson. I’ve asked him to go home now and write up a full statement to give you as much information as possible. Once that’s done, you’ll have to speak with him on a formal witness basis, of course. Usual procedures will apply. Make sure you keep a team with no overlap to DI Callanach on this matter. You can have DS Lively and DC Monroe. Let me know what other resources you’ll require.’

Graham looked uncomfortable.

‘Is something wrong, Detective Inspector?’ Ava asked.

‘Not that I’m unhappy about being given the case, ma’am, but should we not send this outside MIT? If there’s any question about DI Callanach’s involvement, it might be helpful for him to have it investigated and be cleared by an impartial team.’

‘He’s right,’ Callanach said. ‘You’re going to have to suspend me for the duration of the investigation, too.’