The Enterprise is summoned to space station K-7 for security duty when the station's security forces are considered inadequate to guard a shipment of valuable grain by the standards of Federation agriculture administrator Baris. A shipload of Klingons stops off at the station as well, which has all parties concerned even more about the grain consignment. Kirk orders stepped-up security, but that only results in some of the crew - including Scotty and Chekov - instigating a massive bar brawl with the Klingons. All the while, the seemingly harmless huckster Cyrano Jones is trying to peddle furry tribbles off to anyone with a few credits, and Uhura buys one and takes it back to the Enterprise, not knowing that tribbles do only two things: eat and breed. William Campbell returns in the Deep Space Nine story "Blood Oath" to wreak further havoc - sans Tribbles.
