Markham (Ray Milland) fears that a prince traveling with a mysterious girl may be a notorious killer.

Markham (Ray Milland) goes after art thieves who murdered a museum guard.

Markham tries to locate a fortune stolen from a small country. Private Investigator Markham (Ray Milland) goes to Paris to check on a lovely Spanish lady. Coleen Gray is the lady in question and she's very fetching.

Young woman hires Markham to probe seance cult involving her wealthy aunt.

Markham's client: a Canadian industrialist accused of assault. A Canadian mining executive faces an assault charge.

An ex-lawyer suspects that killers are trailing his daughter---to get back at him.

A crank's bombing of empty buildings finally kills a man.

A newspaper gossip item aids Markham's probe of a series of jewel thefts.

Markham, on vacation in Venice, helps a woman prove she's not a killer.

A bank hires Markham (Ray Milland) to look into the fatal shooting of a wealthy client.

Missing pearls trigger Markham's protection of a young girl who says she knows nothing about them.

A missing man's wife is haunted by the fear that she may have accidentally killed him.

Counterfeit stamps are flooding the London rare-stamp market.

A woman thinks her husband ran off with another woman and asks Markham (Ray Milland) to find him.

A Mexican boy is charged with killing an anthropologist.

On vacation in Guatemala, Markham is asked to find a woman's vanished husband.

Ray Milland as the private Investigator is called to Hollywood when a multi-million dollar studio is being sabotaged.

A rich beauty is killed in a boat "accident" and Markham has an address book full of suspects.

Death threats prompt an actress to hire Markham for protection.

An English girl with a large Swiss bank account is trying to keep her finances secret from her government.

Markham's nephew asks his uncle's protection when he visits an eccentric family.

Kitty Brady (Jean Howell) is sure the death of her trucker father was no accident.

A ship's first mate is infected by a deadly South Seas virus that threatens a plague.

Charged with murder: the victim's son.

An old friend asks Markham to help clear a woman suspected of murder.

Markham uses a fake jewel theft to smoke out a vital witness in East Africa.

Roy Markham returns to his apartment one night and finds a chloroformed girl there. Then three hoodlums step out of the next room and tell Markham they are going to use his apartment as a hideout until ransom is paid for the kidnaped girl.

An old schoolmate asks Markham (Ray Milland) to save him from a murderous woman.

Markham becomes a target for an assassin when he is hired to impersonate mysterious international financier Max Bossman—whose enemies are numerous the world over— but Markham finds some pleasure in the assignment because he travels across Europe with Bossman's wife, Friday.

Two crooked cops pursue a small boy who saw them kill a gangster.

Markham flies to Honolulu to investigate a woman's claim that her husband is trying to kill her.

An ex-con hires Markham to find his daughter---whom he's never seen.