The Federation is in competition with the Klingons for an alliance with the inhabitants of Capella IV. The Capellans are a warrior tribe and there is dissension among them as to who to sign the mining rights treaty with. McCoy is familiar with their customs having once spent several months there. When a Capellan, who clearly favors the Klingons, stages a coup, Kirk, Spock and McCoy flee with the now dead leader's wife, who is about to give birth. Meanwhile, the Enterprise receives a distress call from a Federation vessel under attack and, with Scotty in command, leaves orbit.