When Christmas Carol, a Defender of Claus, is suddenly yanked into a portal by her Elven grandmother, she doesn't immediately understand what's happening.

But all becomes clear when she and the Ancient One emerge on the other side of the portal in what's supposed to be the North Pole: everything's changed.

Carol's father is gone. The Defenders of Claus don't exist. The Elf kingdom has been destroyed. And Santa's a broken shell of himself.

The jolly world Carol knew has turned into a terrifying place, where the magic of Christmas has been eliminated and everyone lives in fear of the all-powerful Supreme Leader. Someone has traveled back in time to change history, and Carol's pretty sure she knows the culprit.

Carol and her grandmother, with the help of two ragged boys who have lost everything in the rebellion against the Supreme Leader, track down the only Elf capable of helping their enemy travel through time. The bitter, shimmering creature reluctantly agrees to send Carol back, and she lands in the mid-1800s, when Santa was just getting started and the very first Defender of Claus was found. She must protect Santa and the original Defender and undo the damage her enemy has done or risk returning to a present day that has never known Christmas.