Nevertheless, Strike had an incurable habit of thoroughness. It would no more have occurred to him to skimp on the interview than to spend the day lying in his underpants on his camp bed, smoking. Both by inclination and by training, because he owed himself respect quite as much as the client, he proceeded with the meticulousness for which, in the army, he had been both feted and detested.

‘Can we back up briefly and go through the day preceding her death? What time did you arrive for work?’

‘Nine, same as always. Took over from Colin.’

‘Do you keep a log of who goes in and out of the building?’

‘Yeah, we sign everyone in and out, ’cept residents. There’s a book at the desk.’

‘Can you remember who went in and out that day?’

Wilson hesitated.

‘John Bristow came to see his sister early that morning, didn’t he?’ prompted Strike. ‘But she’d told you not to let him up?’

‘He’s told you that, has he?’ asked Wilson, looking faintly relieved. ‘Yeah, she did. But I felt sorry for the man, y’know? He had a contrac’ to give back to her; he was worried about it, so I let him go up.’

‘Had anyone else come into the building that you know of?’

‘Yeah, Lechsinka was already there. She’s one of the cleaners. She always arrives at seven; she was mopping the stairwell when I got in. Nobody else came until the guy from the security comp’ny, to service the alarms. We get it done every six months. He musta come around nine forty; something like that.’

‘Was this someone you knew, the man from the security firm?’

‘No, he was a new guy. Very young. They always send someone diff’rent. Missus Bestigui and Lula were still at home, so I let him into the middle flat, and showed him where the control panel was an’ got him started. Lula went out while I was still in there, showin’ the guy the fuse box an’ the panic buttons.’

‘You saw her go out, did you?’

‘Yeah, she passed the open door.’

‘Did she say hello?’

‘No.’

‘You said she usually did?’

‘I don’t think she noticed me. She looked like she was in a hurry. She was going to see her sick mother.’

‘How d’you know, if she didn’t speak to you?’

‘Inquest,’ said Wilson succinctly. ‘After I’d shown the security guy where everything was, I went back downstairs, an’ after Missus Bestigui went out, I let him into their flat to check that system too. He didn’t need me tuh stay with him there; the positions of the fuse boxes and panic buttons are the same in all the flats.’

‘Where was Mr Bestigui?’

‘He’d already left for work. Eight he leaves, every day.’

Three men in hard hats and fluorescent yellow jackets entered the café and sat at a neighbouring table, newspapers under their arms, work boots clogged with filth.

‘How long would you say you were away from the desk each time you were with the security guy?’