At that, the professor’s grip tightened, and his hand steadied a moment. “No. No, I think I shall keep it. Just in case the colonel is being … difficult.”

As the minutes passed and they waited for the rest of the party to get back with the key, Liza became increasingly convinced that the colonel was not, in fact, being difficult. It had been long enough with no noise from his room that he was either asleep, exhibiting remarkable self-control, or—and this was fast becoming the most likely possibility—very, very dead.

When Mr Burgh arrived he looked pale, positively drawn. “I’ve spoken to Mary,” he said, which prompted a sharp “Who’s Mary?” from all the guests except the professor, who didn’t seem to care. “She works here? You’ve all seen her multiple times. About this tall.” He held his hand at his shoulder height. “Brown curly hair? I know hotel staff are meant to be invisible, but this is an unusual situation. I thought you might have paid some attention, especially since there are only two of them around at the moment.”

“We’ve been a bit distracted,” explained Liza.

“Because of the murders,” added Sir Richard.

“Although it was also actually probably a bit classist of us,” Hanna admitted. “Especially since some people”—she glared at Sir Richard—”have made her their prime suspect.”

Looking increasingly bored, Ruby folded her arms. “Perhaps rather than wringing our hands about our failure to get on first-name terms with the staff, we could at least get the door open.”

“I was just going to say,” continued Mr Burgh only slightly peevishly, “that I spoke to Mary and she said that there was no answer when she came to deliver his breakfast either, so she left it inside because she assumed he was asleep.”

“A bold assumption, in the context,” observed Ruby.

Mr Burgh carefully unlocked the door and pushed it open. There was a slight dragging sound as he did so—roughly the sound you might expect from an abandoned and rapidly cooling breakfast tray being forced aside.

The good news was that there was no answering gunfire.

The less good news was that the reason there was no answering gunfire was that its occupant was in absolutely no condition to fire a gun.