The series begins with the arrive of spring in Moominvalley. Moomin, along with Little My, Moominpappa and Moominmamma wake up in Moominhouse, while Snufkin also comes back from his south travel on the first day of spring. The first eight episodes create coherent storyline that is based on the third novel, Finn Family Moomintroll. During the story, Moomin and his friends find out the magical silk hat, that turns out to belong to the Hobgoblin. He later gets his hat back from the Moomin family. The Moomins later find a wrecked boat, fix it and travel to a lonely island which is full of Hattifatteners. Next, two small creatures called Thingumy and Bob with a large suitcase arrive to the Moominhouse, and they are followed by the Groke. After the Moomins manage to evict the Groke from their way by giving her Moomin's seashell, it turns out that Thingumy and Bob are keeping the large "King's Ruby" in their suitcase. After Thingummy and Bob return Moominmamma's missing handbag, the Moomins celebrate the event with a large junket, where suddenly the Hobgoblin also arrives. Finally the problem of the King's Ruby's ownership is solved with the Hobgoblin's magic.