Lieutenant Holst of Copenhagen has to help a Russian countess who claims her brother-in-law aims to kill her.
The Mysterious Death on the Underground Railway
Five Hundred Carats
Cell 13
The Secret of the Manifique
The Absent-Minded Coterie
The Sensible Action of Lieutenant Hoist
The Superfluous Finger
Anonymous Letters
The Moabite Cypher
The Secret of the Foxhunter
The Missing Q.C's
The Looting of the Species Room
The Mystery of the Amber Beads