Star Trek III: The Search for Spock

As the USS Enterprise returns to spacedocks for repair at   the continuation of the battle of Khan in 2285, Kirk still cries the death of Spock. McCoy is suddenly enclosed in quarters of the Vulcain, stuttering an incoherent manner. The new planet formed by Genesis is decreed out of limits by the commandment of Starfleet. Kirk is then informed that the USS Enterprise is going to be put out of order.

In quarters of Kirk, Sarek, the father of Spock, confronts the Admiral. The former wants the body of his son. He has to find the coffin on the planet of genesis and, because Spock's spirit has linked to McCoy's at the last minute,   transfering thus his "katra", the doctor must equally return to planet Vulcan. Kirk and crew run into a bunch of renegade Klingons who want to exploit the Genesis planet into a weapon...