Christmas in Camelot by Mary Pope Osborne

This longer, more magical installment sends Jack and Annie to the legendary kingdom of Camelot, which is under a mysterious curse. They must find the “Water of Memory and Imagination” to restore joy to King Arthur’s court. Along the way, they face challenges from enchanted forests, dangerous knights, and icy rivers. The adventure is rich in fantasy and legend, with themes of heroism and belief. It marks the beginning of a new, more epic arc in the series.