The Youth Trap
They stand helpless before an alien who dooms them… to infancy!

Summary
"Captain's log, stardate 31:09.5. Enterprise under full power in Galaxy Zekbran to investigate the sighting of an uncharted planet. All systems operational…"

As the Enterprise scans the planet, no readings of life can be found. Suddenly an alarm goes off and the ship shudders. It is reported that Number Two Engine is taking a beating and may explode!  Just as quickly as it started, the attack ends. Scott reports to Captain Kirk and Spock that every filament part, even those in storage, was burned out by the attack, a part that the engines require to operate. Spock notes that they must find a deposit of Zutotanium. An Engineering team beams down to the planet to take samples and look for the metal. 

On the planet, Burns and Lane, the two engineers, begin their sample taking and discover that the rocks are full of the metal. As Kirk responds, a strange noise occurs, and they Kirk loses contact with them. Minutes later, they hear a response, it sounds like two children playing. Spock, Kirk, and Dr. McCoy beam down to the planet and find two children playing with a rock pile. They children seem to be Burns and Lane.

As Kirk begins to radio the Enterprise, Spock pushes him down as a beam zaps by. they race toward concealment and Spock points out two aliens across the way, firing the beams from a tripod mounted machine. As they're entering the cave, McCoy is hit, and is transformed into a teenager. Kirk calls the Enterprise and has them beam up Burns, Lane, and McCoy before he and Spock make their way across the canyon toward the aliens. As they do so, Kirk is struck by the beam, and Spock notes that the aliens are speaking Esperanta.

Spock pulls Kirk into cover and they notice that the two aliens are fighting with each other, with one pushing the other off the edge of the cliff. Kirk and Spock drag his battered body into shelter as the other alien fires randomly at them. The alien introduces himself as Laiko from the Galaxy Trann, and tells them that he was on an exploratory mission when they had an engine failure and crash landed. Laiko and another of the crew, Kooba, built a machine, but as they were preparing to use it, Kooba slipped and it fired at a nearby lizard. The lizard was transformed into a young pup. They thought that they could adjust the machine to freeze people's ages and were testing it on Burns and Lane, and then McCoy.

Kirk noticed that the other alien, Kooba, was taking the machine away, back toward the alien ship. The trio follow him and learn that he intends to use it as a weapon against the rest of the alien crew, installing himself as their leader. As the aliens question his authority, Kooba transforms the ship's captain into a baby. As this happens, the ledge that Kirk, Spock, and Laiko watch from cracks and begins to slide down the hillside.

As the strange sled arrives at the bottom of the hill, they engage in hand to hand combat with the aliens, but are overwhelmed by the sheer numerical advantage that the aliens hold. Kooba threatens them, but notes that they are more valuable to him alive because he plans to return to his homeworld and take over leadership there. However, the alien ship is disabled, but Kooba plans to assume command of the Enterprise, which flies overhead.

Spock radios up to the ship and Scotty beams him up, along with Kooba and one of the alien guards, Gorg. Kooba has the entire crew stand before television screens, with the intent of firing the age-ray at them over the airwaves. Kooba triggers the ray, and everyone de-ages almost five years instantly, with the rest of the de-aging effect expected to take a matter of hours. 

Kooba has Gorg beam him to the surface where he intends to turn Kirk into an infant. Kirk avoids the shot and grabs a tin plate and reflects the next shot at one of the guards. Kooba continues to fire at him, and Kirk reflects the shots, eventually hitting Kooba and transforming him into a babe. Kirk quickly frees Laiko, but with Gorg at the transporter controls, they have no way of returning to the ship above.

with some quick work, Kirk disguises himself as Kooba, and he and Laiko transport up, and are able to quickly overpower Gorg. Unfortunately, the entire crew has turned into youths. Laiko adjusts the machine and repeats what Kooba did earlier, and the crew begins to return to their original ages.

Kirk and Spock return to the planet with Laiko. They return the aliens to their original ages, with the exception of Kooba, before smashing the machine. An engineering team mines some of the Zutotanium for the engine filaments and makes the required repairs. Once complete, Kirk submits a report to Starfleet Command, and tells Spock that the response questioned whether he and the crew had gone "a little space happy."

Memorable quotes
"Suffering sun spots – Our two engineers… they've been reduced to five-year-olds!"
"Yes, Captain!  And that teen-ager – it is Dr. McCoy as a youth!"
- Kirk and Spock

"Where in flying asteroids are they?"
"Whaaa? I-I see it… but I don't believe it! Captain Kirk… Mr. Spock!  L-look here!"
"Hi Daddy Kirk and Uncle Spock!"
"Are you going to play rock pile with us?"
- Kirk, McCoy, Burns, and Lane

"Looks like we've got our hands full, Spock! What is our change of nailing that machine and escaping?"
"Nil, Captain."
- Kirk and Spock, estimating their odds of success

Background information 
This story was reprinted in Enterprise Log 1 and a later reprint of that volume from the Star Trek: The Key Collection series.
This is the only photo cover to feature the entire main cast. Unfortunately a blemish mars Uhura's face.

Creators
Based on Star Trek created by Gene Roddenberry
Writer: Dick Wood
Artist: Alberto Giolitti, Giovanni Ticci (inks)

Characters

 James T. Kirk  Enterprise captain.
 Spock  Vulcan Enterprise exec and science officer.
 Leonard McCoy  Enterprise chief medical officer.
 Montgomery Scott  Enterprise chief engineer.
Hikaru Sulu Enterprise helmsman. Sulu did not appear in the story, but was pictured on the cover.
Uhura Enterprise communications officer. Uhura did not appear in the story, but was pictured on the cover.
Pavel Chekov Enterprise navigator. Chekov did not appear in the story, but was pictured on the cover.
Christine Chapel Enterprise nurse. Chapel did not appear in the story, but was pictured on the cover.

Others
BurnsSpace-ore expert aboard the Enterprise. See non-canon characters for further appearances of Burns.
LaneSpace-ore expert aboard the Enterprise.
LaikoAn alien scientist from the Galaxy Trann.
KoobaLaiko's assistant, and later the alien leader.
GorgAn alien guard.

References
EsperantaThe interplanetary space language.
TrannA star system, referred to as a "galaxy", that was the origin of Laiko.
 ZutotaniumA rare metal from which starship engine filaments are made.

Youth Trap, The