In this animated horror comedy, a cowardly dog named Courage must rescue his lovely owner, Muriel from a vengeful supernatural Fog. Eustace, Muriel's greedy husband, refuses to return the gold necklace belonging to the Fog's long lost love.

With Mystery, Inc. on the tail of a strange object in Nowhere, Kansas, the strange hometown of Eustice, Muriel, and Courage, the gang soon find themselves contending with a giant cicada monster and her winged warriors.