Things spin out of control when Cyd travels back to Christmas the year before to try and figure out the perfect gift for Shelby. Meanwhile, Barry and Naldo's Winter Wonderland experiment sparks an elf war with Bret and Chet leading the charge.

When Shelby's adventurous Grandma Rita comes to visit, the girls learn time travelers were responsible for setting up Shelby's grandparents and they jump to the 1950s to investigate.