In the heart of a deep, enchanted winter, the beloved Moomins face their first cold season after sleeping through every other. When the rest of the family decides to continue their hibernation, the curious and brave Moomintroll, voiced by Bill Skarsgård, awakens to a world transformed into a silent, sparkling wonderland. Guided by new friends and the spirited Little My, he embarks on a magical adventure to understand the mysteries of frost, snow, and the elusive Christmas spirit that seems to have forgotten their valley. Their quest brings them face-to-face with a lonely, misunderstood creature and the daunting task of helping a weary Father Christmas, voiced by Stellan Skarsgård, rediscover his joy. This beautifully animated family film, featuring Alicia Vikander, blends gentle humor with a poignant and heartwarming tale about friendship, discovery, and the courage to bring light back to the darkest time of the year.