Convinced that Mud is responsible for the disappearance of the school hamster that he was taking care of for the weekend, Junior Blossom is determined that the dog should be tried for his "crime."
Disasters befall the Blossom family as Pap falls into a dumpster and cannot get out, Junior tries desperately to make a success of his secret invention, and Vern dreads letting a new friend meet his unusual family.