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: Lee Cronin (Gene L. Coon)
Writer: Arthur Heinemann
Dir.: Judd Taylor

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
Compton: Geoffrey Binney

Stardate 5710.5

A distress call leads the Enterprise to Scalos. With the call come visual signals showing a city and 5 citizens left of a population of 900 000. When they arrive, they can hear only buzzing sounds and they find a deserted planet. One of the landing party tastes the water .... and disappears. Back on board Kirk feels as if someone touches him, but cannot see anybody. Frequently calls coem in that the ship suffers several damages: The deflector shields break down, so does the communication system. 

As they want to investigate another incident, only Spock and Kirk can pass an energy field, the guards cannot. Spock suggests to be cautious, because it looks like the field he has measured on the planet and it looks as if they are lead into a trap. They enter the machine room and find an apparatus which is connected with the ventilation system. Any try to approach the thing is prevented. Kirk feels pushed backwards and they know: It is not an energy force but beings who prevent them from touching the device. 

Summarizing the events Spock says that they want to show the apparatus to demonstrate their superiority. Spock asks the computer about the presence of foreign life forms: Positive. Other questions are not answered because of lack of data. Kirk suggest to wait what happens next. Before drinking his coffee, the captain hears the buzzing sounds and his coffee is tempered with. He drinks and disappears, too. Now Kirk has joined the Scalosians on board by becoming as accelerated as they are. While he seems to be normal all others seem motionless. Only the Scalosians seem to move normally. Kirk meets Compton, who lives in the same speed as he does now. Kirk learns that he now is accelerated, too. To overwhelm Compton, Kirk fights him and renders him unconsciousness. 

Later he learns that the tiniest injury causes a person accelerated to that speed to age in that speed. Compton dies while he is unconscious. Deela, a Scalosian leader, confronts her companion: Why did you say he's killed him? It was you. Now he thinks he's killed one of his men. In the medical laboratory Kirk speaks on a tape while he sees Spock and McCoy working on the cofe he drank to develop an antidote. The leader, Deela, plans to repopulate their planet with the help of humans. Kirk leaves a tape with all tghe information on he could find. Before Spock finds it he runs the Scalosianian message again on high speed - and finds the buzzing they heard. 

Meanwhile McCoy finds the tape Kirk had left and calls Spock- he's found a tape with the buzzing on it. Running the tape very slowly they learn that the people of Scalos are accelerated and the men sterile bringing their surviving is in jeopardy. And that the Enterprise is in danger. Kirk prevents the Scalosians to beam down by sabotaging the transporter. Scotty suggests to cut the wall and approach the device from the back and Spock reminds him of the acceleration. When Scotty says: "Then we must adjust to their level" Spock agrees to his logic. 

Spock and McCoy find an antidote and Spock drinks the water which accelerates him onto the level of Kirk. The Scalosians have started the device which lowers the degrees on the Enterprise extremely – to destroy them after they have beamed down with the captain. The accelerated Spock meets his captain, who has taken the weapon from Deela and escaped from her. Spock and Kirk destroy the device. Deela knows that now all ships int he galaxy will be warned about their planet and no ship will approach it again. They are bound to die. After saying bye-bye Kirk beams them back onto their planet. Spock says that it is not tested yet while give him the antidote. The speeding down Kirk gets back to the others while Spock stays in the speed to do a lot of repairs onboard in nanoseconds of time.