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

Top Cast

William ShatnerAdmiral James T. Kirk

DeForest KelleyDr. Leonard 'Bones' McCoy

James DoohanCaptain Montgomery 'Scotty' Scott

George TakeiCmdr. Hikaru Sulu

Walter KoenigCmdr. Pavel Chekov

Nichelle NicholsCmdr. Uhura

Christopher LloydCmdr. Kruge

Robin CurtisLt. Saavik