When Stink discovers that Pluto has been downgraded from a planet to a dwarf planet, he launches a campaign in his classroom to restore its status to that of a full-fledged member of the solar system.

"The lucky penny in Judy Moody's pocket sure does seem to be working. She can't stop winning-at bowling, spelling, the unbeatable Prize Claw, everything! For sure and absolute positive, she'll ride that wave of good fortune all the way to Washington, D.C."--

Stink may be a super science freak, but even Dr. Stinkelstein is feeling freaked out about having a slime mold living and growing in his very own room. At Saturday Science Club, Stink learns that these one-celled organisms are smart enough to find their way out of mazes and gang up on food sources.