Nancy and her Labrador puppy, Chocolate Chip, are enjoying the holiday party at the Dashing Dog salon. They even win the raffle prize -- a one-of-a-kind doggie collar with rhinestones shaped like bones. But then the collar vanishes! Now Nancy is digging up suspects. There's Petra, a girl from her school. She really, really wanted the collar for her dog, Prince Fabian. And what about Alice Cahill, who writes about pets for the local newspaper? She was crazy for the collar, too. Then there's Mrs. Vanderpool and her two yipping Yorkies -- the collar is just their style. To solve this case, Nancy has to be sure she's barking up the right tree!