Vance, an independently wealthy college educator, amateur detective, uses his deductive skills and psychological knowledge to help his friend New York County Attorney solve the murder of Archer Coe. At first he thought of suicide when Coe's body was found in a room locked from the inside with all the windows closed. As usual, the action takes place in New York. Vance's methods are unconventional and run counter to the more stringent police investigation methods and legal requirements of a lawyer.