When Josh tells the substitute math teacher unfamiliar with his excuses that his homework was stolen by unique robbers along with his entertainment system, Mr. Farber seems to believe him. Afterward, Josh finds the science snakes he told scornful bully Patrick were in his backpack actually there, is robbed just like in his story, and a menacing boy shows up claiming to be his older military-school dropout brother Frank - a character he made up to threaten Patrick. Everyone suddenly believes that the things happening are the truth even when he admits they're not, and his excuse of why his parents can't be told of his getting in trouble lands them in Hawaii. Everything he says comes true, which creates problems when he has to deal with Frank, ninja mercenaries, Sting Borden attacking him, and a mummy coming to life...