There are no real surprises in this meandering journey to the final frontier, in which Admiral Kirk hijacks the starship Enterprise to help in the rejuvenation of the deceased Spock on the planet Genesis. It's a good character-driven story, undermined by Leonard Nimoy's workmanlike direction, a pseudo-mystical ending and an all-pervasive funereal tone that permeates every frame. However, the amazing special effects supply enough wonder and emotional charge to prevent the third big-screen outing from turning into nothing more than a bloated TV episode.

A surprise visit from Spock's father provides a startling revelation: McCoy is harboring Spock's living essence.