‘I’ve thought and thought about how the killer got in, and I’m sure he must have followed her inside when she came in that morning, because of Derrick Wilson leaving his desk and being in the bathroom. I thought Wilson ought to have been bloody sacked for it, actually. If you ask me, he was having a sneaky sleep in the back room. I don’t know how the killer would have known the key code, but I’m sure that’s when he must have got in.’

‘Do you think you’d be able to recognise the man’s voice again? The one you heard shouting?’

‘I doubt it,’ she said. ‘It was just a man’s voice. It could have been anyone. There was nothing unusual about it. I mean, afterwards I thought, Was it Duffield?’ she said, gazing at him intently, ‘because I’d heard Duffield shouting upstairs, once before, from the top landing. Wilson had to throw him out; Duffield was trying to kick in Lula’s door. I never understood what a girl with her looks was doing with someone like Duffield,’ she added in parenthesis.

‘Some women say he’s sexy,’ agreed Ursula, emptying the wine bottle into her glass, ‘but I can’t see the appeal. He’s just skanky and horrible.’

‘It’s not even,’ said Tansy, twisting the loose diamond ring again, ‘as though he’s got money.’

‘But you don’t think it was his voice you heard that night?’

‘Well, like I say, it could have been,’ she said impatiently, with a small shrug of her thin shoulders. ‘He’s got an alibi, though, hasn’t he? Loads of people said he was nowhere near Kentigern Gardens the night Lula was killed. He spent part of it at Ciara Porter’s, didn’t he? Bitch,’ Tansy added, with a small, tight smile. ‘Sleeping with her best friend’s boyfriend.’

‘Were they sleeping together?’ asked Strike.

‘Oh, what do you think?’ laughed Ursula, as though the question was too naive for words. ‘I know Ciara Porter, she modelled in this charity fashion show I was involved in setting up. She’s such an airhead and such a slut.’

The coffees had arrived, along with Strike’s sticky toffee pudding.

‘I’m sorry, John, but Lula didn’t have very good taste in friends,’ said Tansy, sipping her espresso. ‘There was Ciara, and then there was that Bryony Radford. Not that she was a friend, exactly, but I wouldn’t trust her as far as I could throw her.’

‘Who’s Bryony?’ asked Strike disingenuously, for he remembered who she was.

‘Make-up artist. Charges a fortune, and such a bloody bitch,’ said Ursula. ‘I used her once, before one of the Gorbachev Foundation balls, and afterwards she told ev—’