Stardates: 5371.3-- The Enterprise encounters a cloud creature that feeds on the energy of the planets that lie in its path. Spock mind melds with the entity and tells it that it is killing life and he persuades it to return to its place of origin.
original airdate--September 22,1973
Starships: U.S.S. Enterprise NCC-1701
Trivia: When the cloud creature threatened the populated planet of Mantilles, Kirk ordered that the ship's self destruct system be armed, and he was prepared to blow up the ship to destroy the cloud's "brain." The self detruct system was used in several original series episodes.