A pair of children discover a strange, furry creature and a peculiar set of toys that possess advanced, unknown capabilities. The children, Emma and Scott, bring these items home, unaware of their true origin or the profound implications they hold. Their parents, Jo and David, soon realize that the toys, particularly a small, cat-like creature called Mimzy, are far more than they appear, exhibiting intelligence and abilities that defy current understanding and attracting the attention of those who seek to control such power.

The story is recognized for its imaginative premise and its exploration of profound scientific and philosophical themes through the lens of childhood innocence. The narrative effectively blends elements of science fiction with a focus on the human element, particularly the children's connection to the titular creature. Critics and readers often note the story's ability to provoke thought about the future, technology, and the nature of intelligence. The blend of wonder and underlying tension creates a compelling narrative that resonates with audiences interested in speculative fiction.