After a man is encased in a strange dark cloud whilst on a yacht, he soon becomes increasingly thinner - and smaller. The spectacle brings him fame - but turns him into a tyrant.

While on a boating trip, Scott Carey is exposed to a radioactive cloud. Nothing seems amiss at first, but several months later Scott realizes that he's shrunk in height by several inches. He sees a doctor, who admits that he's baffled. As Scott continues to shrink, decreasing to three feet tall, he becomes bitter, and lashes out at his wife, Louise. He begins to fear a cure will never be found -- since even as he becomes a national sensation, he's still shrinking.