When an evil alien is turned into a mist by an experiment, the mist arrives on Earth and settles into the hat of a Metropolis motorist. The hat influences the driver into trying to drive his car into a children's playground. Superman stops the car and grabs the motorist. When the hat blows away, the motorist cannot recall why he tried to drive through the playground. Superman lets him go, but when the hat finds another owner the same inexplicable crime almost happens again. Eventually Superman figures out that the hat is behind the problem. He notices the alien mist and freezes it. He then sends it into space where it can do no more harm.