Saturnin Dax and his mannered if methodical techniques this time applied to the blackmail of a cabinet minister's daughter who pays out to prevent the publication of forged letters which will make a traitor of her father. After a first murder, and a second, Dax lines up the others involved- a forger, an actress, a gigolo, a member of the police force and finally the man who covered mirrors. The logic as before, and for some, the irritants too.