Story tells of a demented woman out to kill private eye Anthony George. The instrument of death, as it turned out, was, a wild stallion she stocked on her ranch. Her motive was revenge. On a previous …

Checkmate comes to the aid of a woman with a traumatic past when it becomes evident that someone is trying to make it appear she's mentally unstable. discrediting her eye-witness testimony at a murd…

A girl shows up at Corey's apartment, claiming that she is running from someone who is trying to kill her. However, the detectives all find that nothing she has said checks out, including her numerous…

Barbara Rush plays a dual role in The dark divide. Why should Margaret Russell's life be threatened? Her aunt keeps getting phone calls from a woman named Nikki Garnett, threatening Margaret. What mot…

Attorney Emory Olivant invites Corey, Sills and Dr. Hyatt to a party. Once all the guests have arrived, Olivant announces that they are going to play a game—a murder game in which he will be the kil…

Arguably the finest episode of the series, featuring guest star Peter Lorre as an ex-con criminal mastermind determined to wreak revenge on master criminologist Sebastian Cabot. An intricate series o…

A woman believes her husband has killed her male friend, who can not be found. She hires Checkmate to investigate.

Lola Tuscany, a temperamental lady soprano, is having premonitions of her death. After her concert she is almost poisoned and Checkmate Inc. is hired to keep her safe. Don Corey is skeptical, believin…

After two attempts on his life, big game hunter Lee Tabor brings Dr. Hyatt and Carl to his home in the Malayan jungle. He asks for their help in finding out which of his three house guests is trying t…

""Ex-convict Griff Nolan is jealous because his wife Libby earns more as a magazine editor than he does as a mechanic. More domestic strife develops when Griff becomes jealous of Libby's boss Lewis B…

Eve Arden, plays a fashion designer, worried that someone is out to destroy her and her business. Checkmate have two main suspects.

A fictional state governor running for re-election stages a phony assassination attempt to boost his chances for victory, and hires Checkmate, ostensibly for protection, but in reality to provide an a…

Luther Gage, an egomaniacal, methodical killer whom Dr. Hyatt helped send to prison, vows revenge and conducts a plot planned to the last detail to carry it out. Checkmate employs the services of Chri…

At Corey's urging, a reluctant Dr. Hyatt is staying at a lodge for some much needed rest and recreation. The lodge's handyman is plotting the death of the owner, with the help of an escaped convict. T…

Jocko, a man whom Dr. Hyatt recommended be remanded to a psychiatric facility for treatment at his parole hearing five years earlier, still holds a grudge, believing that Hyatt wanted him confined for…

Gina Burton is a photo-journalist who has pictures that prove sensitive to a prominent men's club. In an effort to fend off an intruder trying to gain possession of the pictures while she's developing…

The son of a prominent businessman has been murdered in San Felipe. The town suspects Juan Moreno, a migrant worker, but the men at Checkmate think he is being railroaded. They investigate, and in the…

Sid Caesar appears as Johnny Wilder, a highly popular but guilt-ridden, somewhat neurotic San Francisco disk jockey who believes that a former rival whose own career went on the skids blames Johnny an…

Zoe Kamens is an artist who just wants to paint honestly by copying masterpieces, but her husband, a man of questionable ethics, has been pressuring her to make copies and pass them off as originals. …

Highly successful construction engineer Howard Gentry calls on Checkmate after an apparent attempt on his life. Checkmate suspects his identical twin brother Robert, but Howard does everything he can …

Police Lieutenant Dave Harker, a friend of Don's, is bitter after being denied a promotion to Captain, and decides to frame nightclub owner and high school rival Nick Culley, whom he blames for the pa…

An amnesiac woman is taken home from the hospital by a man claiming to be her husband, but the woman doesn't believe that she could be his wife, and despite her memory lapse believes she has reason to…

In a mostly comedic episode, Jack Benny guest stars as Jack Bowen, a beloved TV comedian much like Benny himself, who is serving as the Grand Marshal of the Pioneer Bowl Parade and football game. Also…

Jed poses as a publicity man on a movie set to keep a close watch on suicidal actress Vicky Page, accused of trying to kill another actress who she suspects is having an affair with her boyfriend, dir…

Checkmate is called to investigate the disappearance of an employee at Venus West, a beauty farm for women. Don finds himself falling for the beauty center's manager, who is not all she seems.

Eddie Phillips is a gifted but troubled young art student with an anger management problem. After being informed of his father's arrest on embezzlement charges, he attacks Dr. Hyatt and is put on a ye…

A widow who runs a yacht club hires the Checkmate agency to investigate an apparent attempt on the life of a married man she is having an affair with, who happens to be a member of the club.

John Baker, a lawyer friend of Dr. Hyatt's with a mysterious past, is threatened with disbarment. He decides he wants to die, and asks a friend to arrange for his death, then changes his mind. When hi…

Aging theater star Richard Gilmore is nearly killed in an apparent accident during a rehearsal. His wife, actress Beatrice Lawlor, suspects it was no accident, and consults Checkmate. A subsequent att…

Victor Ragar, a cellist at a music conservatory that fronts for an Eastern Bloc freedom movement of which he is the leader, is in danger of being assassinated by a compatriot who accuses him of betray…

Karen Vale, who served five years for acting as a courier for enemy agents, is staying at a halfway house for women run by a senator's widow, Mrs. Creighton, and faces the hostility of her fellow citi…

Jed and Dr. Hyatt go undercover as members of a hobo community to protect a man known as Doc, acknowledged leader of the community. Years ago Doc was disinherited by his wealthy father for behaving ir…

The death of powerful business magnate Arnold Brack from an apparent gun accident, and his widow's and brother's apparent lack of emotion, leaves his grieving son, Daniel, to suspect it was no acciden…

Two convicts, both former Catholic schoolboys, escape by shooting a policeman, then hole up in a monastery while Dr. Hyatt is visiting and hold the Father Abbot and Dr. Hyatt hostage. Dr. Hyatt appeal…

Checkmate is hired to protect the life of Judge Leland McIntyre, who is conducting a series of lectures concerning a trial over which he presided eight years ago resulting in him sending a man to the …

Checkmate is hired to protect rodeo star Len Kobalsky from his girlfriend Marcy Lowell's brother, who disapproves of their relationship and prefers she marry someone from a wealthy family such as thei…

A woman who runs a home for struggling artists has been receiving death threats, and suspicion falls on her boarders, including a pretty young poet who is the object of Jed's affections.

The Checkmate team is in Chinatown on behalf of a colleague of Dr. Hyatt's, a Dr. James Low, who claims his Chinese wife may try to kill a man who is supposedly blackmailing her in an attempt to ingra…

Checkmate is hired by a woman to protect her husband, Stephen Jordan, who publishes a newspaper opposed to a referendum on legalized gambling in the city of Midvale. He has been receiving death threat…

In a tour-de-force performance, Don Taylor guest stars as an ex-pro football player, now fronting a cheap health club and always on the make for one big score. Wealthy thrill seekers enlist him in an …

Wealthy industrialist Frederick Haley, who has been appointed to an important position at a humanitarian foundation, asks Checkmate to find out who has been threatening his mistress, whom he plans to …

After an attempt is made on the life of bankrupt ranch owner Harl Stoner, the Checkmate agency goes undercover at the ranch's stockholder's meeting, where a ruthless business man sets out to take the …

When a powerful millionaire dies, his three sons suddenly start to suspect everyone as potential threats to stealing the old man's fortune, including each other. They hire the Checkmate agency to keep…

A young hotel convention hostess is being used to escort businessmen attending the convention to their rooms, and then have her picture taken with them for the purpose of blackmail. The proprietress, …

The personal relationship between entertainer Johnny Kay and his singing partner Pete O'Mara has hit a sour note. Corey (Anthony George), who has been asked to keep a protective eye on them, shows up…