“Just sometimes. You know, she wanted to let her hair down a bit, but they had been going out together for years . . .”

“Did she drink a lot?”

“Oh, no! She didn’t drink at all, or smoke. She was a fitness freak, always dieting, and her room at the flat was a no-smoking zone.”

Tennison stubbed out her fifth cigarette of the session, not that she was counting. “What about drugs?”

They shook their heads in unison, Tennison thought a little too eagerly.

“You mean never? Not just a little grass or speed?”

Lady Antonia twisted her hands in her lap. “Karen didn’t like drugs, hated any of us having stuff in the flat. She wouldn’t touch anything like that.”

“Not even coke? Did she use cocaine?”

“No, honestly. We’ve known each other for years, since school, and she got quite uptight about that sort of thing.”

Tennison sighed. “OK, so what about Michael, she was a virgin as well, I suppose?”

Lady Antonia crossed her long legs and fiddled with the top of her boot. “That was her business, I have no idea what she did in private.”

“Now it’s my business, love. Karen was found in a prostitute’s room, and I have to find out how she got there. Come on, what do you take me for? Are you trying to tell me that four girls, living in the same flat, never even mentioned sex?”

Lady Antonia pursed her lips. “I don’t think you have any right to ask us that sort of question.”

Tennison was getting more irritated by the second. “I have every right, as I said before. Anyway, that’s it for now, but I might need to talk to you all again before you leave. This officer will show you the way back to the canteen, go and have some coffee.”

Lady Antonia faced Tennison. “I am going to complain about the way we have been treated, as if we were criminals. And we don’t want to go back to that awful canteen. Please would you call my father, if you need to speak to us we are perfectly willing, but we have been here for . . . we really . . . I would like to go home.”

Tennison never took her eyes off the girl’s face. The bravado disappeared fast, and Antonia blinked back the tears. “Please, let us go home. We’ve been here for hours.”