The Search for Spock

The damaged Enterprise returns to Earth, its crew still grieving for Spock. Starfleet intends to scrap the ship and declares the Genesis planet off limits. McCoy begins acting strangely, even speaking in Spock's voice, and Spock's father Sarek visits Kirk with an explanation: before he died, Spock placed his katra, his living spirit, in McCoy's mind. Both must be taken to Vulcan, along with Spock's body, or McCoy may not survive. The body, however, lies on Genesis, and Starfleet refuses to let Kirk go back.

So Kirk and his friends break the rules. Uhura deals with a transporter officer, Scotty sabotages the new USS Excelsior so it cannot give chase, and Kirk, McCoy, Scotty, Sulu and Chekov steal the Enterprise. On Genesis, Saavik and David Marcus find Spock alive, reborn as a child whose body is ageing rapidly along with the unstable planet. David admits he used protomatter, a dangerous shortcut, to make Genesis work. The Klingon commander Kruge, convinced Genesis is a weapon, destroys the science ship Grissom and takes them prisoner.

When the Enterprise arrives, Kruge demands the secret of Genesis, and David is killed by one of his warriors. Kirk sets his own ship to self-destruct, wiping out the Klingon boarding party, and watches from the planet as the Enterprise burns across the sky. He fights Kruge on the collapsing world and sends him into a fiery chasm, then tricks his way aboard the Klingon Bird-of-Prey and escapes with Spock, now fully grown again. On Vulcan, the high priestess T'Lar performs the ancient fal-tor-pan ceremony to reunite Spock's spirit and body, a ritual that puts McCoy at great risk. Spock emerges unsteady and uncertain, but as he looks at Kirk, the memories begin to return, and he speaks his friend's name: Jim.