This 7-year series chronicled the adventures of the Impossible Mission Taskforce (IMF), a team of government spies and specialists who were assigned "impossible missions" by the unseen "Secretary". Although the cast varied over the years, the main characters included The Team Leader (Dan Briggs the first season, then Jim Phelps the other six), The Techno-Wizard (Barney Collier), The Strongman (Willy Armitage), The Master of Disguise (first Rollin Hand, then The Amazing Paris), and The Femme Fatale (Cinnamon Carter, Casey, Dana Lambert, Mimi Davis). 　　The series is best known for its opening mission assignment (conducted by a pre-recorded tape), the theme composed by Lalo Schifrin, the leader's selection of mission agents from a dossier, the opening briefing, the intricate use of disguises and a typical "mask pulloff" scene near the end of most episodes, and the relative lack of characterization of the characters.