"Catspaw" is the seventh episode of the second season of the American science fiction television series Star Trek[1] Written by Robert Bloch and directed by Joseph Pevney, it was first broadcast October 27, 1967.

Contact has been lost with the landing party, consisting of Chief Engineer Scott, Lt. Sulu, and Crewman Jackson.

His open mouth emits an eerie voice, telling Captain Kirk that Enterprise is cursed and must leave the planet immediately, or death will follow.

Kirk and the others attempt to overpower them but suddenly find themselves in another part of the castle, with a robed man, Korob, and the black cat, whom he appears to consult for advice.

Korob then surrounds the model of the ship with a crystal prism, informing them that Enterprise has been encased in an impenetrable force field.

Sylvia tells Kirk that she and Korob are explorers from another galaxy, who wield their power through a device called a transmuter, which gives them control over matter.

Korob comes to free Kirk and Spock, telling them that he has released their ship, and urges them to leave immediately, as he can no longer keep Sylvia under control.

Chief Engineer DeSalle previously appeared in the episodes, "The Squire of Gothos" and "This Side of Paradise" wearing a gold command shirt.

The list noted that the episode was written by Robert Bloch, writer of the famous psychological thriller Psycho.