Spock's Brain
Episode 1 of 24 within Season Three. Item 57 of 90 overall.
Production number 0043-61.
Lee Cronin - Writer
Marc Daniels - Director
382 votes

Stardate: 5431.4--5432.3--A woman from a strange alien ship transports to the Enterprise.She stuns everyone on the bridge with a device on her forearm and takes an interest in Spock.

However, when Kirk and McCoy wake up, they discover that that the woman has taken Spock's brain! They rig up something to keep his body alive but even a Vulcan can only survive a limited time without a brain, so they must track down the woman's ship and recover the missing organ.

original airdate--September 20, 1968  

network: NBC

music:"Theme from Star Trek" "Where No Man Has Gone Before" by Alexander Courage 


Alien Races: Sigma Draconians

Log Entries:

  • "Captain's log, Stardate 5431.4. For fifteen hours and twenty minutes we have been following the ion trail of the spaceship that has Spock's brain. Time left to us, eight hours and forty minutes."
  • "Captain's log, Stardate 5431.5. We are beaming down to a primitive glaciated planet in the Sigma Draconis star system. Time left to us to find Spock's brain, eight hours and twenty nine minutes."
  • "Captain's log, Stardate 5431.6. Immediately after making contact with Spock's brain, Doctor McCoy, Engineer Scott, and myself were taken prisoner inside a highly complex civilization hundreds of meters below the surface of planet Sigma Draconis Seven. The primitive creature we encountered above warned us about the givers of pain and delight and the frightening consequences of being captured by them."
  • "Captain's log, Stardate 5432.3. Doctor McCoy is proceeding to restore Spock's brain. Our problem, we do not know how long his increased surgical knowledge will stay with him. Any additional attempt to use the teaching device is impossible. It would kill my medical officer."
  • "Captain's log, supplemental. Our race against time to save Spock's life may prove futile. Doctor McCoy has lost the surgical knowledge he obtained from the teacher. He has been drawing on his own skills and surgical techniques in an attempt to continue the operation, but he is faltering and uncertain. In a desperate hope that he can draw on Spock's brain for assistance, I instructed Doctor McCoy to give priority to connecting Spock's vocal chords."


Space: the final frontier. These are the voyages of the starship Enterprise. Its five-year mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before.

Klingon: logh: Qav'e'. DaH 'entepray' Duj lengmey lutalu'. Qu' vagh qaStaHvIS DIS: Huj chu' qo', yISam yIn chu' tayqeq chu', vay' bolDly nuqDaq V pagh 'ej eQplore.

related items

Previous episode :
056 Assignment: Earth (season finale)
Next episode :
058 The Enterprise Incident

alternative title

Also known as - Klingon=yab spock

regional titles

Spock's Brain
Spock's Brain
Le cerveau de Spock
Spocks Gehirn
Brain Spock ar
Operazione cervello
El cerebro de Spock