Season: 1
Original Airdate:October 6, 1966
Writer(s): Richard Matheson
Director(s):Leo Penn
Guest Stars
Jim Goodwin as Farrell
Edward Madden as Fisher
Eddie Paskey as Connors
Garland Thompson as Wilson
Don Eitner as photo double for Capt. James Kirk
Stardate: 1672.1
Synopsis: A transporter malfunction splits Kirk into good-Kirk and evil-Kirk.