When Moomin wakes up early from his winter hibernation, he finds himself completely alone for the first time in an unfamiliar world, as Moominvalley has been covered by the icy veil of the Lady of the Cold. Initially searching for someone to take care of him and wanting to drive away the winter, young Moomin embarks on a journey into the unknown. Through this tender adventure, he learns to make new friendships and to offer help to those in greater need than himself.