Billy and Rusty spill a mysterious red dye on to Billy's white mouse Marmaduke. Immediately the mouse grows very large and runs away. The red liquid has also run into the creek as well. All sorts of animals drink creek water...

Suddenly there are rumors of albino bandicoots and kangaroos and mysterious monsters seen around the district! Hunting parties and television news' squads and scared neighbours run amok. Billy and Rusty have to act fast to get out of this mess, retrieve Marmaduke...and maybe find a way to fix this colossal problem before it gets seriously (and literally!) out of hand.