‘Are you absolutely sure that the man you heard was Tony?’

‘Yes, of course.’

‘You didn’t see him, though?’

‘I…’ Bristow’s rabbity face was suddenly puzzled. ‘… no, I – I don’t think I actually saw him. But I heard him let himself in. I heard his voice from the hall.’

‘You don’t think that, perhaps, because you were expecting Tony, you assumed it was Tony?’

Another pause.

Then, in a changed voice:

‘Are you saying Tony wasn’t there?’

‘I just want to know how certain you are that he was.’

‘Well… until this moment, I was completely certain. Nobody else has got a key to my mother’s flat. It couldn’t have been anyone except Tony.’

‘So you heard someone let themselves into the flat. You heard a male voice. Was he talking to your mother, or to Lula?’

‘Er…’ Bristow’s large front teeth were much in evidence as he pondered the question. ‘I heard him come in. I think I heard him speaking to Lula…’

‘And you heard him leave?’

‘Yes. I heard him walk down the hall. I heard the door close.’

‘When Lula said goodbye to you, did she make any mention of Tony having just been there?’

More silence. Bristow raised a hand to his mouth, thinking.

‘I – she hugged me, that’s all I… Yes, I think she said she’d spoken to Tony. Or did she? Did I assume she’d spoken to him, because I thought…? But if it wasn’t my uncle, who was it?’

Strike waited. Bristow stared at the pavement, thinking.

‘But it must have been him. Lula must have seen whoever it was, and not thought their presence remarkable, and who else could that have been, except Tony? Who else would have had a key?’

‘How many keys are there?’

‘Four. Three spares.’

‘That’s a lot.’

‘Well, Lula and Tony and I all had one. Mum liked us all to be able to let ourselves in and out, especially while she’s been ill.’

‘And all these keys are present and accounted for, are they?’

‘Yes – well, I think so. I assume Lula’s came back to my mother with all her other things. Tony’s still got his, I’ve got mine, and my mother’s… I expect it’s somewhere in the flat.’

‘So you aren’t aware of any key that’s been lost?’

‘No.’

‘And none of you has ever lent your key to anyone?’

‘My God, why would we do that?’

‘I keep remembering how that file of photographs was removed from Lula’s laptop while it was in your mother’s flat. If there’s another key floating around…’

‘There can’t be,’ said Bristow. ‘This is… I… why are you saying Tony wasn’t there? He must have been. He says he saw me through the door.’

‘You went into the office on the way back from Lula’s, right?’

‘Yes.’

‘To get files?’