Plot outline

The Enterprise

USS Enterprise (NCC-1701)

The USS Enterprise, NCC-1701, is a fictional starship in the Star Trek media franchise. The original Star Trek series depicts her crew's mission "to explore strange new worlds; to seek out new life and new civilizations; to boldly go where no man has gone before" under the command of Captain James...

encounters a giant cloud creature that feeds on the energy of the planets that lie in its path. They determine it is heading for Mantilles, home to a Federation

United Federation of Planets

The United Federation of Planets, also known as "The Federation" is a fictional interplanetary federal republic depicted in the Star Trek television series and motion pictures...

 colony governed by former Starfleet officer Bob Wesley (featured in the TOS episode "The Ultimate Computer)".

The Enterprise must discover a way to head off this threat before Mantilles is destroyed. Kirk takes the Enterprise inside the cloud in an attempt to stop it. Once inside, the ship loses power and Spock realizes that the cloud is an intelligent being which can be reasoned with. Spock mindmelds with the entity and tells it that it is killing life and attempts to persuade it to return to its place of origin. The creature then comprehends that its source of food—planets—are populated by many small living beings. It agrees to leave the Enterprise alone and to depart from this galaxy.

Commentary

"One of Our Planets is Missing" is regarded by some entertainment critics to be "one of the best [shows] that animated [Trek] spin-off has to offer" and "a highly satisfying episode that nicely encapsulates the Star Trek philosophy. The show's "animation competently conveys the size and scope of the marauding cloud" which threatens the Federation world of Mantilles. Spock's "mind-meld with the cloud is both logical and satisfying, and Kirk and Spock's wrestling with the need to protect [all] life-forms is intelligent and provocative." Kirk even discusses the rationalisation for his decision "not to kill today" by referencing a line from the live action Trek episode "A Taste of Armageddon".

The episode is also noted for its many plot similarities to Star Trek: The Motion Picture

Star Trek: The Motion Picture

Star Trek: The Motion Picture is a 1979 American science fiction film released by Paramount Pictures. It is the first film based on the Star Trek television series. The film is set in the twenty-third century, when a mysterious and immensely powerful alien cloud called V'Ger approaches the Earth,...

.