Star Trek III: The Search for Spock

The plot picks up shortly after the conclusion of the previous film. When McCoy begins acting irrationally, Kirk learns that Spock, in his final moments, transferred his katra, his living spirit, to the doctor. To save McCoy from emotional ruin, Kirk and crew steal the Enterprise and violate the quarantine of the Genesis Planet to retrieve Spock, his body regenerated by the rapidly dying planet itself, in the hope that body and soul can be rejoined. However, bent on obtaining the secret of Genesis for themselves, a renegade Klingon (Christopher Lloyd) and his crew interfere, with deadly consequences.