"The Enemy Within"
Series Star Trek
Season 1, Episode 5
TOS 1x04 003
Air date October 6th, 1966
Writers Richard Matheson
Director Leo Penn
Producers Gene Roddenberry; Robert H. Justman; John D.F. Black
Starring William Shatner; Leonard Nimoy
Episode guide
"The Naked Time"
"Mudd's Women"

"The Enemy Within" is the fifth episode of season one of the American science fiction television series Star Trek. It was directed by Leo Penn and written by Richard Matheson based on story concepts originally developed by Gene Roddenberry. It first aired on NBC on October 6th, 1966.

Synopsis Edit

Cast Edit

Principal Cast Edit

Actor Role
William Shatner Captain James T. Kirk
Leonard Nimoy Mister Spock

Guest Stars Edit

Actor Role
DeForest Kelley Doctor Leonard "Bones" McCoy
Grace Lee Whitney Yeoman Janice Rand
Nichelle Nichols Nyota Uhura (voice only)
George Takei Ensign Hikaru Sulu
James Doohan Montgomery Scott
Edward Madden Technician Fisher
Garland Thompson Technician Wilson
Jim Goodwin Lieutenant John Farrell
Eddie Paskey Lieutenant Ed Leslie

Notes & Trivia Edit

Allusions Edit

Bloopers Edit

Quotes Edit

See also Edit


The World of Star Trek

Star Trek miscellaneous

External Links Edit