Rex and his Elves' gang develop the umpteenth plan to rob Pixieville's bank: thanks to the ravenous Molesaurs, digging creatures that live in the city underground, they'll be able to open a hole in the vault, avoiding Mr. Grind's traps. The plan doesn't exactly go like Rex had thought and both the Elves and the Pixies get sucked in underground, while Pixieville, on its surface, is full of holes!