This is a somewhat odd episode, in that it was written by science fiction author Larry Niven, and contains the Kzinti, a crossover alien species featured in Niven's Known Space setting. Besides this, the episode was based off a short story previously written by Niven, The Soft Weapon, and adapted to Star Trek by replacing some of the characters with Spock, Uhura, and Sulu.

Because of this background, the episode is rather different from other Star Trek episodes. Firstly, Kirk is absent, for the only time in the entire run of original cast Star Trek from The Man Trap all the way to the film Star Trek VI: The Undiscovered Country. But perhaps even more noticeably, it feels different. The story has more of a hard science edge than is usual for Star Trek, and a more tangible feeling of depth, back-story, and characterisation to the otherwise one-off aliens they encounter. It definitely plays differently to most other episodes, and is the better for it.

Even if the Kzinti are too stupid to realise that an intelligent spy weapon that believes it has fallen into enemy hands probably shouldn't be trusted.

Transcript

1
First Officer's log, Stardate 4187.3. Shuttlecraft Copernicus en route to Starbase 25 with a Slaver stasis box.
Sulu: The box! {it is glowing}
Spock: There must be another stasis box on this planet.
2
{on planet in the Beta Lyrae system}
Sulu: Kzinti pirates!
Spock: They do not respect women, or vegetarians.
Sulu: Kinda like Texas then?
Spock: The grumpy one is a telepath. Think about eating chili. With beans and no meat.
3
Chuft Captain: A Slaver weapon! With many settings: knife, screwdriver, corkscrew...
Kzinti Telepath: Police web deactivator! The prisoners!
{Sulu and Spock escape}
4
Chuft Captain: {on Sulu's screen} We will trade the female hostage for the weapon!
Spock: Let us see what else this does.
SFX: NUKE!
Sulu: We can't give them THAT!
5
Chuft Captain: We have the weapon!
Weapon: I am a Slaver spy tool, and you are an enemy.
Chuft Captain: Tell us how to access your weaponry!
Weapon: Twist my widdershins until you reach the null position.
Caption: actual line
6
SFX: Kaboom!
Uhura: A self-destruct booby trap!
Sulu: Why didn't they leave it alone?
Spock: Curiosity, it seems, killed the cat.