Napoleon Marvel, gentleman of the road, lives a hand to mouth existence, begging and stealing what he needs and making his bed where he can. Passing through Westingborough one summer night he is startled by the barking of a dog, coming from the empty house belonging to Bernard Wymering. Fleeing from three sinister figures who appear from nowhere and threaten him with a knife, Marvel discovers that the house is far from empty - it contains the mutilated corpse of Wymering himself.
Investigating the killing, Inspector Head must untangle a web of intrigue to get at the truth of this bloody deed. What was the significance of the burnt film cans found near the victim? And when is a dog not a dog?
Originally published in 1937, this is a vintage murder mystery from the golden age of detection.