Gene Hackman stars as Harry Caul, a surveillance expert whose regular work is taping the lives and conversations of others. The opening shot of the film is a slow, long zoom into Union Square in San Francisco, where a young couple, Mark (Frederic Forrest) and Ann (Cindy Williams), are having what seems like a mundane conversation while Harry and his assistant, Stanley (John Cazale), eavesdrop from a nearby van. But when Harry carefully analyzes his tape of the two, he uncovers bits of an unsettling dialogue. Harry is suspicious of his client's motives for wanting the tape, and he becomes uncharacteristically caring about the people he may have put in danger. In Harry Caul, Francis Ford Coppola has created a complex Catholic-guilt ridden character for which Gene Hackman is perfect: a man in complete control on the outside but breaking down within. Robert Duvall appears in the film in an uncredited cameo role as the Director. Teri Garr, Harrison Ford, and Elizabeth MacRae costar, but Hackman, in top form in every scene, is the reason for watching.