Down-on-their luck brothers, Lars and Ernie Smuntz, aren't happy with the crumbling old mansion they inherit... until they discover the estate is worth millions. Before they can cash in, they have to rid the house of its single, stubborn occupant—a tiny and tenacious mouse.
Sniffles the mouse and his friend the Bookworm decide to take up egg collecting, setting their eyes upon a big barn owl egg. But the big barn owl isn't so hot on the idea.