Journey to Babel

The Enterprise is en route to an important Federation conference on a planet code-named Babel. Traveling aboard are delegates from many worlds, including Vulcan's Ambassador Sarek and his Terran wife Amanda--revealed as Mr. Spock's parents. Spock and his father have not spoken for 20 years, a fact that causes embarrassment for Kirk, but not for his first officer. The journey is also complicated by an unidentified vessel following the Enterprise and tension between various delegates, especially Sarek and Tellarite Ambassador Gav. When Gav is murdered, Sarek is the prime suspect. The stress reveals Sarek is suffering from a heart condition and needs an immediate operation to save his life. Only his son can serve as the blood donor, but when Captain Kirk is attacked and stabbed by Thelev, a member of the Andorian party, Spock assumes command. Despite the danger to his father's life, he refuses to step down until the unidentified ship following the Enterprise is stopped. Spock's mother is unsuccessful in her appeals to her son to permit the operation to be performed. Kirk fakes a return to the bridge to trick Spock into reporting to sick bay. The vessel, an Orion ship, attacks and is destroyed. Thelev is exposed as a surgically altered Orion posing as an Andorian and commits suicide on the bridge. The operation on Sarek is successful and the ambassador resumes diplomatic relations with his son.