Still smiling, Sir Richard continued as if nothing had happened. “—having a gun is a far less assured means of self-protection than the colonel has been suggesting.”

“Yet,” observed Ruby, “you still took one.”

“Well, yes, I’m a realist, not a fool. And if you know exactly who is armed and you’ve just told them exactly where to point their weapons—at the door, in this case—or you can be reasonably sure that you’ll know when they’re asleep … well, you’ve just fixed yourself a nice hotel full of sitting ducks.”

From the way Sir Richard was talking, it sounded like he had a solution to propose, and Liza was pretty sure she knew what it was. “You’re going to suggest we stick together until the police get here, aren’t you, so we can keep an eye on each other?”

The other guests exchanged a series of sharp, appraising looks. It was a plan that had been mooted at the very start, and nobody had felt particularly compelled to go along with it then. But that had been three murders ago.

“Clever gir—clever young woman.”

Hanna glared. “You know that isn’t better, right?”

“A thousand apologies.” Sir Richard did not look as if he was offering even one apology. “But you must admit, it solves rather a lot of problems. And if anybody else winds up dead, then when the police arrive, we’ll all be able to say, ‘No, officers, the other five were with us the whole time.’ Good for everybody, what?”

Ruby picked out a couple of ominous notes on the piano. “I hate to say it, but that came perilously close to making sense.”

“I do, from time to time,” said Sir Richard with a smile.

The professor seemed to be thinking. “Hold on. If you were a murderer, mightn’t you also, instead of telling us to go back to our rooms and lock ourselves in where we’ll be safe, gather us all together in one room so that when we go to sleep, you could take us out in one fell swoop?”

Sir Richard shrugged. “Maybe, but the killer hasn’t gone in for the fell swoop option so far.”

“And,” added Reverend Lincoln, “killing everybody at once might actually be quite difficult. Besides, we can sleep in shifts.”

Now Ruby played a tauntingly light-hearted melody. “Oh goodie, sleeping in shifts. My absolute favourite activity.”

Liza and Hanna exchanged glances. On the one hand, it was probably sensible; on the other hand, being stuck in a room full of guns and people they had no reason to trust didn’t seem exactly restful either.