When Horrible Harry's pet cat, Googer, sneaks a ride and gets into the school building, third-graders Harry and Doug have to catch him before anyone else does, which means going into some forbidden places.
Kayla places her tooth in a Tooth Fairy pillow, but it disappears before the Tooth Fairy has a chance to visit--can her dog, King, help Kayla find the missing tooth?
King and Kayla are playing fetch with their friends, Jillian and Thor. Jillian throws King's favorite ball too hard, and now it's gone missing! King and Kayla must put together the clues to figure out where it went---and who has it.