Space hippies searching for a mythical planet steal a shuttle and trigger a chain of disasters.
The Enterprise picks up a group of young people who are searching for Eden, a mythical planet, and whose leader, Dr. Sevrin, is a brilliant scientist who has been dismissed. The group takes control of the ship, and Spock, who shares their interest in a better world, joins them for a time. The planet turns out to be dangerous.
The episode is a satirical look at the counterculture of the 1960s, with lively songs and a clash of generations. Spock plays an instrument with the group. Fans are divided, with some finding it cringe-worthy and others cherishing its camp charm, which has given it a lasting reputation.