A Jolly Bad Fellow

A research scientist (Leo McKern) discovers a poison gas that will kill a man by making him literally laugh himself to death without leaving any trace of foul play. He soon decides to play God and winnow down the human race by killing all of those he deems unworthy of existence. At the same time he's conducting his experiment, the scientist is also competing for a prestigious professorship and being pursued by his seductive assistant (Janet Munro). …