"Journey to Babel" is the tenth episode of the second season of the American science fiction television series Star Trek.

The episode features the first appearance of Sarek (Mark Lenard) and Amanda (Jane Wyatt), the parents of Spock, and also introduces two new species, the Andorians and the Tellarites.

The system is a prime source of dilithium crystals, but is underpopulated and unprotected, a situation some would prefer to maintain by keeping Coridan out of the Federation.

Captain Kirk learns that Sarek is in fact Spock's father, now estranged because he had disapproved of his son's decision to join Starfleet rather than attend the Vulcan Science Academy.

Gav takes offense at the allegation and the confrontation briefly becomes physical before Kirk intervenes, warning all parties to keep order on his ship.

Meanwhile, Communications Officer Lt. Uhura has detected an encoded transmission beamed from Enterprise to a fast-moving vessel at the extreme edge of sensor range.

Shortly afterward, Ambassador Gav is found murdered, his neck broken by what Spock describes as an ancient Vulcan method of execution called Tal-Shaya, casting suspicion on Sarek.

During questioning, Sarek suffers a cardiovascular event, and is rushed to the sickbay, where Chief Medical Officer McCoy determines that he requires immediate surgery.

When Uhura picks up another encoded transmission from inside Enterprise and traces the source to the brig, Kirk decides to stay on the bridge.

Sarek replies, "At the time, it seemed the logical thing to do," and offers Amanda his hand in a ritual gesture of affection.

[8] The episode introduced Spock's parents, Sarek and Amanda, who never again appeared in the series, but became major characters across the Star Trek franchise.

They note the episode features the Star Trek franchise aliens, Vulcans, Andorians, and Tellarites in additions to humans going to a space conference.