Captain Kirk responds to a distress call from planet Beta XII-A only to discover the Federation colony there destroyed and a band of Klingons as the only suspects. Klingon commander Kang, however, accuses Kirk of disabling his own ship and attempts to take control of the U.S.S. Enterprise NCC-1701. The culprit actually turns out to be an unknown energy being which thrives on the destruction and conflict. The energy being sends the Enterprise warping out of control as the confrontation with the Klingons intensifies. Kirk ultimately convinces Kang that they must set aside their differences in order to drive the alien being from the ship, and the two defeat their common enemy.
