Jack and Foxie attend Doggeroo Dog Show with Sarge and Auntie Tidge, and straightaway Jack is paw-deep in a new mystery. Dogs are mysteriously ending up covered in mud just before their classes. The dogs all deny that they're doing it on purpose, so Jack sets out on the trail of the phantom mudder. Before he discovers the criminal, he has a close encounter with some scented pooch polish. It's amazing what a dog detective will do in the line of duty!