While on a boating holiday, Scott Carey is exposed to a cloud of radioactive spray. A few weeks later, following a series of medical examinations, he can no longer deny the extraordinary truth. Not only is he losing weight, he is also shorter than he was. Scott Carey has begun to shrink.
At first Carey tries to continue some kind of normal life. Later, having left human contact behind, he must survive in a world where spiders and insects are giant enemies. And even that is only a stage on his ultimate journey into the unknown.