Mission: Impossible - Season 1 - Eps 21: Snowball in Hell
A former prison guard, Sefra, has got hold of a supply of cesium 138, which explodes at temperatures above 70 degrees. Sefra plans to sell the sample and the formula from the closed-down prison base where he once worked. Rollin and Barney go in as a photographer and model respectively, and Sefra ""learns"" that Barney is a former prisoner returning for revenge. The team fakes a generator break down while Sefra beats Barney, and the cesium starts to heat up. Sefra has it taken to a nearby hospital refrigerator, where the IMF makes the switch. When Sefra discovers the missing jar, he forces Barney to show him the escape route which he supposedly used to escape. As Sefra makes his own escape, the IMF send the cesium sample toward him on a remote-controlled mini-tank, and it blows up, killing Sefra and making sure no one gets the formula or the sample.
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)