Sasspants, Hamisher, and the other animals at "Mr. Venezi's Pets and Stuff" store think a dragon may have moved into the shop unnoticed. That is a problem. Other problems still need solving too--like helping Mr. Venezi tell the difference between bills and fan mail.
When guinea pig Sasspants leaves Mr. Venezi's pet shop to live with Detective Pickles, and hamster-detective Hamisher retires, the other animals must try to solve the case of the missing bookstore cat must be solved without their help.
Eleven-year-old Lottie runs into a new neighbor in town who has magic stronger than her own, and the pet shop's newest arrival, Giles the hamster, helps out with his courageous, bossy personality.
Everyone is afraid of Mr. Walnut, the scowling owner of the biggest pet store in the city, who sells all kinds of animals to rich customers from out of town, but when Mina's pet rabbit goes missing she vows to do something about it.
Guinea pig Sasspants knows something is wrong with ninth-grader Viola, the new pet shop assistant, so when Mr. Venezi goes missing Sasspants and Hamisher put their private investigation skills to the test.
Sasspants, the reluctant guinea pig private investigator, is drawn into another mystery by Hamisher the hamster who believes there is a ghost in the pet shop.
Sasspants, a guinea pig, reluctantly agrees to act as a private investigator when Hamisher the hamster begs for her help in discovering who is stealing sandwiches from the pet shop's befuddled owner.
When her parents take her to visit a very special pet store in the park across from her apartment, both Sophie and Mr. and Mrs. Noah, the pet store owners, have their secret wishes fulfilled.
