Mission: Impossible - Season 6 - Eps 18: Committed
Syndicate boss Chandler's alibi is provided by Lt. Governor Harrison, who is in Chandler's pocket. Chandler has the husband of the only witness, Nora Dawson, get her committed and proceeds to have her driven insane at a mental hospital he controls. The IMF must get her out and have her testify in 24 hours. Jim gets Casey committed and she is put in a room near Nora, then he manages to get to Nora's cell and she and Casey switch - Jim then takes Nora-as-Casey out. The team get Nora off the island - when Casey-as-Nora is called to testify, she babbles insanely but then removes her mask while the team bring the real Nora in to testify.
About Mission: Impossible

Title: Mission: Impossible
First Air Date: 1966-09-17
Last Air Date: 1973-03-30
Status: Ended
Rating: 7.6/10 (from 278 votes)
Language: EN
Seasons: 7
Total Episodes: 171
Network: CBS
Genres: Action & Adventure, Crime, Drama
Production Companies: Desilu Productions, Paramount Television
Synopsis
Mission: Impossible is an American television series that was created and initially produced by Bruce Geller. It chronicles the missions of a team of secret government agents known as the Impossible Missions Force. In the first season, the team is led by Dan Briggs, played by Steven Hill; Jim Phelps, played by Peter Graves, takes charge for the remaining seasons. A hallmark of the series shows Briggs or Phelps receiving his instructions on a recording that then self-destructs, followed by the theme music composed by Lalo Schifrin. The series aired on the CBS network from September 1966 to March 1973, then returned to television for two seasons on ABC, from 1988 to 1990, retaining only Graves in the cast. It later inspired a popular series of theatrical motion pictures starring Tom Cruise, beginning in 1996.
Cast

Peter Graves
Jim Phelps

Greg Morris
Barney Collier

Peter Lupus
Willy Armitage

Lynda Day George
Dana Lambert

Bob Johnson
Man on Tape (voice)