Amok Time

Spock grows irritable, stops eating and demands leave on Vulcan without explaining why. Kirk agrees, but Starfleet orders the Enterprise to Altair VI for a presidential inauguration, and Spock quietly sets course for Vulcan anyway. McCoy finds his body chemistry in turmoil, and Spock finally admits the truth: he is in the grip of pon farr, the Vulcan mating drive, and will die unless he goes home to take a mate. Kirk defies orders and takes him there, beaming down with Spock and McCoy. At the ceremony, presided over by the formidable T'Pau, Spock's betrothed T'Pring demands that he fight for her and chooses Kirk as her champion. The combat is to the death. Spock appears to kill his captain, and the shock ends his fever. T'Pring coldly explains that she preferred Stonn. Back aboard, Spock finds Kirk alive: McCoy's injection had only faked death, and Spock briefly shows open joy.