is escorting two robot grain ships to Sherman's Planet to help the colonists survive. They break off to investigate a Klingon cruiser attacking a scout ship. The Klingons refuse to identify themselves and Kirk has Scotty lock onto the pilot with the transporter. The Klingons destroy the scout ship and Scotty tries to recalibrate the transporter, and then the Klingons turn on the Enterprise
. They unleash a new weapon, a field effect that immobilizes all power systems on the ship, including the transporters. However, the energy drain on the Klingon ship is also extreme, preventing them from firing. The Klingon captain, Koloth, finally contacts them. He demands that they turn over the pilot who is wanted for "ecological sabotage." They lose contact with the robot ships, which are out of range of the field effect. Kirk has Sulu use the freighters to ram the Klingon ship then gives Koloth a chance to release the Enterprise
. Koloth realizes what's happening and tries to split the field effect three ways, but only succeeds in overloading his generators. The Klingons disable one robot ship and then flee...Read the full recap
Koloth: It won't work, Captain Kirk. (cuts out)
Kirk: It will work. Or he'd still be gloating.
Cyrano Jones: Captain, these are safe tribbles.
McCoy: There is no such thing as a safe tribble.
Spock: A safe tribble would be a contradiction in terms. Tribbles are well known for their proclivities in multiplication.
Cyrano Jones: And they breed fast, too!
Spock: But apparently, it also immobilizes the attacking ship's abilities at the same time.
Scotty: Aye, and if that's true, then it's a weapon that leaves them as helpless as it does us.
Spock: I believe I just said that, Mr. Scott.
Kirk: Sherman's Planet needs that grain desperately.
Scotty: Aye, sir, but we've got tribbles on the ship, quintotriticale in the corridors, Klingons in the quadrant. It can ruin your whole day, sir.
Kirk: Well, Mr. Spock, do you have any ideas?
Spock: We could always throw tribbles at them.
Kirk: I thought Vulcans didn't have a sense of humor.
Spock: We don't, Captain.
Kirk: Your (enlarged) tribbles are all over my ship. My security men can't find them all.
Cyrano Jones: You need better security men, Captain.
Spock: Aren't you going to sit down, sir?
Kirk: (contemplating the enormous tribble in his chair) I think... I'll stand.
Cyrano Jones: Under space salvage laws, (the Glommer's) mine!
Scotty: A planetary surface isn't covered under space salvage laws. But, if you want the little beastie that bad, Mr. Jones, we'll transport you over with it.
Cyrano Jones: I withdraw my claim.
Korax: (after blasting a super tribble into thousands of little tribbles) Any other orders, sir?
Koloth: Yes. Don't do that again. Ever.
Scotty: But you've got to admit, if we've got to have tribbles, it's best if all our tribbles are little ones.
The tribbles are colored pink because as per the DVD commentary, director Hal Sutherland suffered from color-blindness. The rest of the crew tried to make the correction and get them back to brown but it didn't go through.
Scotty beams Cyrano Jones aboard the Enterprise moments after Sulu announces that the shields have been raised.
When Koloth speaks to Kirk, his image is on the bridge screen, but in one sequence his head appears on the bridge in front of the screen.