The best pal of the dead guy shows up, a personable and pliant young American pilot. With the homoerotic subtext firmly left safely in the closet along with Grant's abandoned claustrophobia, the two go to London to chase down clues. The big break comes when Grant, without a shred of motivation, visits a famed Arabian scholar who admits to having met the victim.

With no other suspects, Tey only pretends to fool us from that point on. The whole sorry affair is wrapped up by a multi-page suicide note from the Arabist who explains that he killed the guy because the guy had discovered the location of Shangri-La. Nope, I'm not making this up.

Inspector Grant returns to work, having dropped his nervous breakdown, the comely noblewoman, and the hot cousin without even a glance backwards. It's an implausible mystery with some lovely scenic writing in the first half. But casting a fly in a Scottish river should not be the most exciting part of a mystery novel. If you're going to advance the art of mystery writing by introducing rich, textured characters, you might be forgiven for weakness in the mystery. But Tey resolves Grant's claustrophobia by having him spend a weekend with Scottish rustics and resolves the mystery through coincidence, mythical lands and an overly-loquacious suicide note.

Where are the Reichenbach Falls when you need them?