A thief named Bill Leighton leaves an empty house, clutching a mysterious gold object. A large Newfoundland dog appears from nowhere, snatches the object and disappears again. The scene is set for another case for the detectives Rip Hilliard and Grant Logan. It is Rip's grandmother who finds the dog the next day and brings him home. She answers an advertisement in the local paper placed by a man looking for a lost Newfoundland. Leighton turns up to claim the dog but Rip smells a rat and pretends the dog has disappeared.