The Blaines spent the next couple of hours in what Liza tended to think of as “a scratchy space.” They weren’t arguing exactly, but each was acutely aware of the many ways they could start an argument if they weren’t careful. For most of the afternoon, Liza had huddled on the floor transferring pictures from her phone to her laptop while Hanna took a long bath.

Staring at digital photographs of footprints was beginning to give Liza a headache, and more than once she’d considered giving up. But Hanna had been right: this would just eat at her if she didn’t at least try to—not solve it, exactly—but do something. Even though it was becoming abundantly clear that she was out of her depth. It wasn’t that she’d expected to be able to look at a couple of marks in the snow and say at once “aha, the killer was five foot, eight inches tall with a florid face, smoking a Trichinopoly cigar,” but she also hadn’t expected it to be quite this hard. She wasn’t even completely sure which of the three unaccounted-for sets of prints went together. Neither the professor nor the killer had been courteous enough to wear shoes that were notably large or small, or characterised with a distinctive tread, or perhaps conveniently embossed with the name of a manufacturer who only ever made three pairs of shoes a year for a very select list of clients. She thought two of them were of a size. And perhaps a little smaller? Possibly a woman? Then again, Belloc’s feet had been pretty small too.

Still, there were some things she really could work out. Some people they couldn’t have belonged to. She, Hanna, and Ruby had been together in the hotel. Sir Richard and his aunt, and the professor and the vicar, had been in pairs when the gun went off. And of course, it was possible that somebody was lying to protect somebody else—especially where Sir Richard and his aunt were concerned. Family protecting family was more likely than strangers protecting strangers, unless there was some kind of you-kill-my-inconvenient-relative-I’ll-kill-your-wife deal going on. But she’d seen all four of them walking towards the woods, and it seemed very improbable that any of them could have shot him, then looped around back to the hotel in time to make it look like they’d just heard the gunshot five minutes later. Of course, somebody could have seen something from the hotel—Ruby’s room was south-facing and so was Mr Burgh’s office—but, “By the way, I saw Mr/Ms X wandering down to the boathouse with a gun,” wasn’t the sort of information you kept to yourself when you were trapped in a hotel with a killer. Still, she filed the possibility away under worth following up on.