Dossier 113 (aka The Blackmailers)

Introducing M. Lecoq widely believed to be the inspiration for Sherlock Holmes

Monsieur Lecoq of the French Sûreté is called to investigate a bank robbery in one of the world's first detective novels, widely credited as the inspiration for Sherlock Holmes.

The book begins with a bank robbery with Fauvel's bank losing 350000 francs. Only two people in the bank had a key and the combination to the safe and they were Fauvel himself and his chief cashier, Prosper Bertomy. The case looks black against the cashier the only one to know about the money being put into the safe from the strong room.

As things look blacker and blacker for prosper amidst double-dealing, blackmail, and murder Monsieur Lecoq of the French Sûreté steps in to prove the young man's innocence in the face of incriminating evidence and unravel the truth behind a seemingly impossible crime.