TAS Season 1 Episode 13 The Slaver Weapon

Plot

On stardate 4187.3, the Enterprise shuttlecraft Copernicus, carrying Science Officer Spock (voiced by Leonard Nimoy), Communications Officer Lt. Uhura (voiced by Nichelle Nichols), and Helmsman Lt. Hikaru Sulu (voiced by George Takei) are en route to Starbase 25 to deliver a stasis box, a rare artifact of the Slaver culture. The now-extinct Slavers used these objects to carry weapons, valuables, scientific instruments and data. The boxes can detect each other and evidence shows that another device is located near Beta Lyrae.
Following the signal, the shuttle lands on an ice planet where the crew is captured by the hostile, catlike Kzinti. The Kzinti had an empty stasis box of their own, and were using it to lure in passing starships. They are trying to steal the boxes in the hopes of finding a super weapon that will return their empire to its former greatness. The Kzinti open the box that the Enterprise had been transporting, finding inside some fresh meat, a picture of a Slaver, and a powerful (but unfamiliar) alien device, which the Kzinti immediately suspect is a weapon.
The weapon passes hands several times between the Federation and Kzinti crews, during which time Sulu discovers a total-conversion beam setting. The Kzinti recapture all three Federation personnel and the weapon. As the Kzinti explore the device's many settings, they discover a war computer that starts talking to them. After the Kzinti fail to provide several code words and ask about the total-conversion beam setting, the weapon concludes that they are enemies and directs them to what it claims is the setting that they want but which is actually a self-destruct setting. When the Kzinti activate that setting it turns out to be a disruptor field that destroys the weapon and kills the Kzinti.