Big Courage in a Seven-Pound Dog.

Two days before Christmas, a golden flash crashes into Zoe’s snowy backyard, and out tumbles Gimble “Piston,” Santa’s lead sleigh mechanic.

During a top-secret test flight of Santa’s new Peppermint Propulsion system, a shy baby reindeer named Spark slipped from the sleigh. Now Spark is lost somewhere in Willowbend, and every time he gets nervous, he turns invisible.

Luckily, Zoe has a plan. Even luckier, she has Miles and his little brother, Bentley.

Miles may be only seven pounds, but he has a mighty nose, a commander’s confidence, and absolutely no patience for Christmas emergencies. Bentley may be smaller, but he is determined to prove that even the littlest Yorkie can help save the day.

With glowing hoofprints to follow, squirrels to manage, and animal control closing in, Zoe, Miles, and Bentley must find Spark before Christmas Eve. But Spark does not need to be chased. He needs to feel safe. And helping one frightened little reindeer find his courage may become Miles and Bentley’s mightiest Christmas mission yet.