Season 4

A racketeer's bookkeeper gets Diamond involved in a blackmail scheme against his boss, when he asks him to find a book and gives him only one hour to do so.

An acquaintance of Diamond's is murdered. At his grave at a potter's field, Diamond sees a wealthy old woman laying flowers at some of the unmarked graves. Diamond tries to find the connection between her and his down-on-his-luck friend.

A bookie decides to get rid of Lt. Kile, whose efforts to put a stop to the bookie's operation have begun to annoy him.

A financier hires Diamond to search for his partner who has gone missing in Mexico.

While briefly stopping in San Francisco, Diamond finds himself the target of a gunman.

Diamond finds himself in a deserted amusement park on the trail of a desperate fugitive murderer.

Diamond is hired to deliver a note to a bank teller and is somewhat surprised when the teller screams after she reads the note.

A marriage counselor whose life has been threatened hires Diamond to protect him.

An old nemesis of Diamond's on the police force has Diamond arrested on murder charges after the girlfriend of an escaped convict is found murdered.

Diamond receives a tip that a man who has been presumed dead for over a year is still alive.

Diamond finds himself in a lonely hearts club when he is hired to investigate the confusing circumstances surrounding a robbery and murder.

Diamond receives a mysterious telephone call which informs him that he will die at a specific time later that evening.

A night club singer hires Diamond to protect her and her band leader from a disgruntled pianist who once played in their band.

A friend of Sam's wants Diamond to prove that her uncle's death was murder.

Summoned to a theater by a phone call, Diamond watches a magician thrust seven swords into a box containing his assistant. Is this the dangerous situation he was called to deal with?

An actress hires Diamond after she learns that a valuable painting which she purchased is a fake.

Diamond follows a dog which is pursuing a bedraggled cat.

After returning to his apartment with a date, Diamond finds an infant abandoned on his couch.

A journalist hires Diamond to look into the death of a singer who fell to her death, which he suspects was a murder but that the police have ruled a suicide.

A landlady finds one of her tenants dead in his room and shortly afterwards is greeted by a gun-wielding stranger looking for the man.

A diplomat who does not want the police to be involved, asks Diamond to find his missing fiancee.

Shortly after a dancer takes out a large insurance policy on her legs, she gets injured by a hit and run driver and is forced to collect on the policy.

A woman is killed after hiring Diamond to protect ""a young lady from France"" who turns out to be a poodle.

A woman hires Diamond when her father is attacked after he finds heroin hidden in his antique store warehouse.

A man is concerned about his daughter, whom he feels has been spending too much time brooding over her husband's death.

A French woman gets threats from a supposedly dead war criminal who knows the whereabouts of a fortune in smuggled diamonds.