Lacey isn't thrilled about being dragged to her late great-uncle's mansion in the mountains, especially since her know-it-all stepsister, Cal, is along for the ride. Lacey's dad wants them to bond, but that's not going to happen
Soon after they arrive, an emergency forces Lacey's dad to leave the two girls on their own. When they take the opportunity to explore, they discover a secret lab, and accidentally let loose a hoard of mischievous creatures into the mansion.
Things look grim for Lacey and Cal until they're contacted by an "otherworldly exterminator" who offers to get rid of the creatures for them. The catch? They have to traverse the Neitherswarth, a heinous alternate dimension, to meet him.
With Lacey's dad due back soon, the girls will have to put aside their differences and work together to get things back to normal