“Shock,” said Alleyn, “seems to have a period of incubation with some people. Now, as you went down in the lift you faced the switchboard?”

“Yes.”

“All the time?”

“Yes.”

“Did you hear any sort of movement behind you?”

“I d-don’t remember hearing anything at all. It’s not long, is it?”

“It’s precisely thirty seconds to the bottom,” said Alleyn. “You don’t go all the way. Did you hear any sort of thud?”

“If I did, I don’t remember it.”

“All right. To go back a little. While your father interviewed Lord Wutherwood, you were all in here, lying on the carpet in that corner.”

Stephen and Colin exchanged glances. Colin silently framed the word “Patch” with his lips.

“No,” said Alleyn. “Lady Patricia only told us you lay on the floor. She said it was a kind of game. We noticed it took place in that corner where a door has been boarded up. There’s a trace of lipstick on the carpet close to the crack under the door and a bit of boot polish farther out. It’s difficult to avoid the presumption that your game involved listening to the conversation next door.”

“I say,” said Stephen suddenly, “do you speak French? Yes, I suppose you do. Yes, of course you do.”

“Shut up,” said Colin.

“I haven’t been lying on the carpet,” said Alleyn. “And Mr. Fox only stayed there long enough to catch a phrase, spoken. I think, by you. ‘ Taisez-vous, donc.’”

“He’s always saying it,” Stephen muttered gloomily. “In English or in French.”

“And a fat lot of notice you take,” Colin pointed out. “If you’d only—”

“We won’t go into that,” said Alleyn. “Now, when this unusual game was ended, and after your brother Michael had come in, you two, with your elder brother, went into the drawing-room, while your sisters went into Flat 26. Did you go together and directly into the drawing-room?”

There was a moment’s silence before Colin answered: “Yes. We all went out together. The girls went first.”

“Henry just had a little snoop d-down the passage.”

“In which direction?”

“Towards the hall. He was only a second or two. He came into the d-drawing-room just after we did.”

“And did you all stay in the drawing-room until Lady Charles came?”

“Yes,” said the twins together.

“I see. That pretty well covers the ground. One more question, and I think I may put it to both of you. You’ll understand that we wouldn’t ask it unless we felt that it was entirely relevant. What impression did you get of Lady Wutherwood during the afternoon?”

“Mad,” said the twins together.

“In the strict sense of the word?”

“Yes,” said Colin. “We all thought so. Mad.”

“I see,” said Alleyn again. “That’s all, I think. Thank you.”

When the twins reappeared in the drawing-room Roberta thought they had a slightly attenuated and shivery air, rather as if they had been efficiently purged by Nanny. They looked coldly at the rest of their family, walked to the sofa and collapsed on it.