Dana Johnson finds a very peculiar egg in his backyard; it is pale green, with large veins lining the sides. When the egg hatches, a yellow, blob creature comes out. Dana piles the creature into a shoe box. Eventually, he decides to take the creature to the scientific laboratory in town. When Dana gets to the lab, he's greeted by a man named Dr. Gray. Dana shows him the creature he's found. Dr. Gray explains that the creature is one of many that came from Mars and fell to Earth. Dr. Gray brings Dana into a cold room. The room contains numerous other egg monsters. Dr. Gray explains that the creatures melt if it gets too hot, so they need to be in a cold environment. Dana is then told he won't be allowed to leave. Dr. Gray proceeds to keep Dana captive, saying that the boy may have contracted alien germs or diseases.
The room Dana is in is so cold that he's worried for his safety. The egg monsters merge into a blanket and warm Dana. The next morning, Dr. Gray sees that the monsters have merged, and he accuses Dana of ruining the creatures. Dr. Gray threatens to kill Dana, but the monsters jump on the scientist. Dana runs away, and he gets his parents. When they return to the laboratory, the egg monsters and Dr. Gray are gone. It is never determined exactly what happened to the scientist.
Dana goes home. After lying in bed for a while, Dana goes outside, feeling incredibly happy. Unexpectedly, he crouches down on a lawn and lays a massive egg.
Dr. Gray is obsessive about his work, and he reveals himself to be deranged by the end of the story.
Dr. Gray is an older man with a wrinkly face. He often wears a white lab coat. He has shiny white hair that's parted in the middle and slicked down on the sides. He has a grayed mustache and pale blue eyes.