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.

"Mrs. Hall says we have to keep writing, it is a dying art. "Good, let it die," I said, and then she said, "You are staying in during recess, Jon Fisher." Jon's teacher has started an interplanetary pen pal program. Much to Jon's annoyance, his pen pal, Straxi, is from Pluto, the most boring, smelliest and far away place possible. And if that wasn't bad enough, she's a girl!"--Back cover.

Infuriated by the declaration that Pluto is no longer a planet, President Penguin and his penguins invade Earth and it is up to Ricky and his robot pal to defeat them--with some help from Ricky's cousin Lucy and her pets.

Who doesn't enjoy a party? And this party is the twins' favorite teacher's wedding.