It's a dark and stormy afternoon when Sasspants, PI(G), leaves Mr. Venezi's pet shop to live with a new owner. Soon there's a mystery afoot back at the shop: the cat from the bookstore next door has disappeared. All the pet shop animals are putting on their detective hats, but their fluffy-but-faraway guinea pig detective can't help them follow the clues! Can Hamisher the hamster solve this cat-napping without Sasspants? He's going to try his furry best not only to crack the case but to reunite with his best friend and fellow sleuth too. Sasspants is a guinea pig with a penchant for puzzles. She lives in a pet shop in which the animals are smarter than the shopkeeper, who mistakes hamsters for koalas, chinchillas for camels, and hermit crabs for tractors. When the "g" falls off the sign on Sass's cage, Hamisher the koala—that is, hamster—is positive she's a Private Eye. And when there are no mysteries to be solved, Hamisher is happy to create some!