When pets go missing on the day of the big parade, Detective Penelope Dolores "PD" McPem is on the case! It's West Bay Primary School's annual Pet Parade and Miss Harnett's Year One class is excited to showcase their lovable companions. Budding detective PD McPem is particularly keen to show off her clever canine assistant, Scooter. But the arrival of her new deskmate, Theodora Putkins, and her Rhinoceros Beetle Circus creates havoc when both Scooter and Mary the beetle are nowhere to be found! Can PD McPem's Agency for Mysterious Mysteries solve the puzzle of the missing pets before it's too late?