A woman in the hospital hires Diamond to trail her ex-husband, who she believes has obtained custody of their daughter to use as cover for his shady business practices.

Diamond finds himself facing off against the mob when is hired by a woman to prove that her fiancee is innocent of killing a man in a hit and run auto accident.

Diamond unravels a story of unrequited love and revenge while tracking down a fugitive gangster who is in the possession of a valuable stolen necklace.

Diamond plays a game of cat and mouse with an escaped convict who bears a grudge against Diamond for bringing him to justice.

Diamond attempts to convince an old war buddy who has turned to a life of crime to give himself up to the authorities.

Diamond is hired to investigate a fire in a fur shop which killed an accountant who was working there.

Diamond is beaten and rendered unconscious by a man he suspects is an art thief. When he recovers he discovers that a beautiful woman has subdued his attacker.

Diamond sets out to find the man who is trying to kill him and who failed in his last attempt, leaving an innocent bystander dead.

Diamond fails in his efforts to protect a shady night club owner who believes that someone is out to kill him.

While investigating the death of an investment counselor, Diamond learns that a letter has recently been stolen from the deceased's attorney.

Diamond and his client are kidnapped by gangsters who threaten to kill both of them unless Diamond reveals the location of valuable paintings from another case.

After a policeman friend of Diamond's is killed while on patrol, Diamond decides to do an investigation of his own to insure that the killer is brought to justice.

Diamond uncovers a narcotics smuggling operation while investigating the murder of an art restorer who was killed in his workshop.