With Julia and Finn on the run with the Alien, it's up to Johnny, Mr. Leopold and a reluctant Tabby to find them. What they don't know is that while Julia is trying to get away from the farm, a subterranean creature is being lured there.

The pursuit of a mysterious new creature catches the attention of the local police. After a particularly close encounter, Mr. Leopold forbids Johnny from continuing the chase, causing a rift between foster father and son.