The Case of the Registered Letter

An unassuming secret-service detective, shaped by a past wrongful conviction and modest manner, investigates a suspicious death after finding a registered-letter blot that points to a distant correspondent. By tracing postal records and retrieving a sealed envelope from a friend, he uncovers a letter addressed to the dead man's beloved that contains a request to hand an enclosed note to the trial judge only if the other suspect is proclaimed guilty. The papers indicate a deliberate suicide meant to implicate an innocent man, and the detective pushes to have the enclosure opened before legal authorities and witnesses to untangle bureaucratic obstacles, personal loyalties, and the truth.