E1 - Death Runs Wild

Aired: September 17, 1960

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 case, the private eye had brought her lover to justice and the gas chamber.

E2 - Interrupted Honeymoon

Aired: September 24, 1960

E3 - The Cyanide Touch

Aired: October 01, 1960

E4 - Lady on the Brink

Aired: October 15, 1960

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 murder trial.

E5 - Face in the Window

Aired: October 22, 1960

E6 - Runaway

Aired: October 29, 1960

E7 - Target: Tycoon

Aired: November 05, 1960

E8 - The Deadly Shadow

Aired: November 12, 1960

E9 - The Dark Divide

Aired: November 19, 1960

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 motive could the woman have?

E10 - Moment of Truth

Aired: November 26, 1960

E11 - The Mask of Vengeance

Aired: December 03, 1960

E12 - The Murder Game

Aired: December 17, 1960

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 killer.

E13 - The Princess in the Tower

Aired: December 31, 1960

E14 - The Terror from the East

Aired: January 07, 1961

E15 - The Human Touch

Aired: January 14, 1961

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 of cat and mouse moves between the two geniuses culminates in a surprise and ultimately poignant ending, befitting the episode title. This episode stresses the close friendships between the three detectives of CHECKMATE INCORPORATED as it contrasts with that of the brilliant, but soulless Lorre. Directing, writing and acting are all exemplary.

E16 - Hour of Execution

Aired: January 21, 1961

E17 - Don't Believe a Word She Says

Aired: January 28, 1961

E18 - Laugh Till I Die

Aired: February 04, 1961

E19 - Between Two Guns

Aired: February 11, 1961

E20 - A Matter of Conscience

Aired: February 18, 1961

E21 - Melody for Murder

Aired: February 25, 1961

E22 - Phantom Lover

Aired: March 04, 1961

E23 - The Gift

Aired: March 11, 1961

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, believing it is a publicity stunt, until he is nearly killed when a bomb explodes in the car he and Lola are driving in.

E24 - One for the Book

Aired: March 18, 1961

E25 - The Paper Killer

Aired: March 25, 1961

E26 - Jungle Castle

Aired: April 01, 1961

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 to kill him.

E27 - The Deadly Silence

Aired: April 08, 1961

E28 - Goodbye Griff

Aired: April 15, 1961

""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 Bates --- and buys a gun."" -- TV Guide

E30 - Voyage Into Fear

Aired: May 06, 1961

E31 - Tight As a Drum

Aired: May 13, 1961

E32 - Death by Design

Aired: May 20, 1961

E33 - The Thrill Seeker

Aired: May 27, 1961

E34 - Hot Wind in a Cold Town

Aired: June 10, 1961

E35 - A Slight Touch of Venom

Aired: June 17, 1961

E36 - State of Shock

Aired: June 24, 1961