Signed, Picpus (Inspector Maigret, #23)

A small, thin man, rather dull to look at, neither young nor old, exuding the stale smell of a bachelor who does not look after himself. He pulls his fingers and cracks his knuckles and tells his tale the way a schoolboy recites his lesson.
A mysterious note predicting the murder of a fortune-teller; a confused old man locked in a Paris apartment; a financier who goes fishing; a South American heiress ... Maigret must make his way through a frustrating maze of clues, suspects and motives to find out what connects them.