The animals in Mr. Venezi's pet shop are used to how forgetful he is. Then he hires the perfect assistant, Viola. She does her job so well that Mr. V hardly needs to be there. In fact, one day, Mr. V doesn't come back at all! But then Viola starts ignoring the animals. Has Mr. V given the pet shop to a villain? Or is some other mystery afoot? Sasspants, PI(G)--fluffy-but-determined guinea pig detective--and junior detective Hamisher the hamster--will soon fish out the answers!