Executive producer: Gene Roddenberry
Associate producers: Edward K. Milkis and Gregg Peters
Producer Fred Freiberger
Co-producer: Robert H. Justman
Story consultant: Arthur H. Singer

Story by: Michael Richards (D. C. Fontana)
Writer: John Meredyth Lucas
Dir.: Herb Wallerstein

Captain Kirk: William Shatner
Science Officer, First Officer, Cmdr. Spock: Leonard Nimoy
Dr. Leonard "Bones" Mc Coy: DeForest Kelly
Lt. Sulu: George Takei
Lieutenant Commander Montgomery Scott: James Doohan
Lieutenant Uhura: Nichelle Nichols
Ensign Chekov: Walter Koenig
Nurse Chapel: Majel Barret
Losira: Lee Meriwether

Kirk, McCoy, Mr. Sulu and Lt. D'Amato beam down to investigate on a planet, leaving Spock in charge of the Enterprise. The moment they are beaming they still can see a woman appearing in the transporter room. She kills an ensign only by touching him. After materializing they try to reach the Enterprise, but she has disappeared. Wherever the woman appears and touches somebody, the person dies. That way Lt. D'Amato is killed on the planet. 

When she appears to kill Mr. Sulu, the others step in and find out that she can only kill the one she's named before. In the meanwhile, the same woman appears on the Enterprise, in various places. Suddenly the ship is violently shaken and all the people on the bridge fall off their chairs. When Uhura asks Spock what has happened, he says, "It seems that the occipital region of my head collided with the command chair base." 

Spock in charge

The Enterprise has been transported many parsecs far away by an unknown force. Spock and Scott wonder about what happened. They come to the conclusion that the woman who has been seen on board has to do with it. When Scott suggests to serch the ship for her, Spock disagrees, saying that a being who can move a starship in space the way she did would not wait for them to find her. After pondering over the situation, Spock decides to go back to the planet where Kirk, McCoy and D'Amato were beamed. He states it is logical to do so, but can't really explain his logic - he's appears to be following a hunch and trying to sell it as logic. Scott does not buy it and questions his decision. What if the Captain and the others were also transported away? To return to the planet will take very long and should they not find their shipmates there, they wouldn't make it back on time to rescue them. Spock replies very coldy that he is the one in charge of the ship and they will follow his orders, unless Mr. Scott is planning to mutiny. Scotty answers "Oh, Mr. Spock!" and subdues. 

Spock pondering
Mr. Scott does not buy

On the planet, Kirk, McCoy and Sulu mange to protect each other, by stepping in whenever the woman calls one of them and tries to reach for him. Going underground on the planet the three discover a computer which has been put there by an ancient race, the Kalandans, by now long dead. The computer projects the killing images in order to protect the planet and its inhabitants. Soon three copies of the same women appear and answer to the question for whom they are coming. All three are in danger now. In the moment of high jeopardy Spock materializes and destroys the computer and saving his friends by destroying the images by that. He had brought back the ship in time which the woman, called Losira, had sent far away.