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

Writer: Meyer Dolinsky
Dir.: David Alexander

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
Parmen: Liam Sullivan
Alexander Michael Dunn

Stardate 5784.0

The Enterprise receives a distress call from the planet Platonius. As Kirk, Spock and McCoy beam down they find Parmen, the planet's leader, slightly wounded. He would die of a small wound like this because the Platonians have no resistance to physical illness though they are highly advanced telekinetic people. Trying to keep a doctor at his side Parmen offers McCoy to stay with them. But when McCoy refuses, all three are kept prisoners on the planet – victims of sadistic and cruel ideas of Parmen and the other Platonians. 

Moving accordingly to whatever Parmen wants them to do – as he can telekinetically steer them, the three are exposed to the sick fantasy of Parmen. Only Alexander, who is exposed to Parmens humiliations as they are, has got no such powers and tries to help them, but in vain. Mrs. Uhura and Sister Chapel are beamed down, too, being misused in the same way. McCoy finds out that that kironide, a chemical subtance natural to the Platonian food, is the reason for the telekinetical powers and mixes it for themselves. Like he always did, Alexander refuses to do anything to gain these powers. Kirk, Spock and McCoy develop powers like the Platonians and thereby can defend themselves. When they leave, they take Alexander with them, who wants to begin a new life on another planet.