He discovers that his wife Ellen ( Susan Clark ) is having an affair with a man named Marty Heller ( Harris Yulin ) .
Harry Moseby ( Gene Hackman ) is a retired professional football player now working as a private investigator in Los Angeles .
Harry Moseby discovers that Harry Moseby 's wife Ellen ( Susan Clark ) is having an affair with a man named Marty Heller ( Harris Yulin ) .
Harry Moseby ( Gene Hackman ) is a retired professional football player now working as a private investigator in Los Angeles .