The Phantom Lake Kids in: The Day the Earth Abruptly Almost Ended.

Phantom Lake County is known for its share of strange occurances, from monster attacks to alien invasions. However, things will never be the same when, after experiencing inexplicable earthquakes emanating from a local system of caves, the area is overrun by grossly mutated creatures of unusual size, a phenomenon that may point to the return of a long-since-forgotten menace! Thankfully, the Phantom Lake Kids are "on the job" and determined to solve the real mystery: What's the deal with Butch's magic hat?