出身基層、道德意識薄弱的譚美貞（田蕊妮飾），為了袒護犯了法的男友（楊明飾），令自己身陷囹圄。幸得律師高哲行（郭晉安飾）在她出獄後，讓她在律師樓工作而重獲新生，並與他漸生情愫。高哲行原本是前途無限的明日之星，但被新紮幹探張立勳（吳卓羲飾）在某次追捕中所傷而成坐輪椅的殘障人士，同時成為二人犯法交易的契機。隨著高哲行連串不可告人的陰謀被揭發，張立勳感情用事，因內疚贖罪去包庇他。譚美貞最後能否背負愛情，做出正確的抉擇呢？
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.
