It's 1940 and CW Briggs (WOODY ALLEN) is one of the best insurance investigators working for North Coast Casualty and Fidelity of New York. A sexist, middle-aged man who enjoys flirting with Jill (ELIZABETH BERKLEY), one of the office secretaries, CW uses his intuition and street connections as much as standard detective measures to crack various insurance claim cases.
Not surprisingly, he doesn't get along with Betty Ann Fitzgerald (HELEN HUNT), the strong-willed and confident efficiency expert who's been shaking up the status quo ever since joining the company. Since she's having an affair with their married office boss, Chris Magruder (DAN AYKROYD), CW must put up with her changes and snide remarks thrown back at him.
Their antagonism is brought to an amusing head at a birthday party for coworker George Bond (WALLACE SHAWN) where Voltan the Magician (DAVID OGDEN STIERS) hypnotizes the two - using a jade scorpion pendant - and makes them believe they're really in love. They then do just that, at least until Voltan breaks the trance, and CW doesn't believe coworker Al (BRIAN MARKINSON) afterwards when he explains what happens.
Nor can the investigator believe that someone is robbing places where he previously installed security systems. Having to deal with both Betty Ann and a rich femme fatale, Laura Kensington (CHARLIZE THERON) while trying to crack those crimes, little does CW know that he's still under Voltan's spell and is repeatedly robbing homes under his command. From that point on, and as he becomes the prime suspect to outside detectives Joe Coopersmith (PETER LINARI) and Herb Coopersmith (MICHAEL MULHEREN), CW does what he can to clear his name all while trying to solve the case.