This episode of "Moominvalley Stories" begins with the aftermath of a terrifying night. Due to the frightening encounter with the Groke, Sniff stays at the Moominhouse, while Snufkin retreats to his tent as usual. The Groke, a chilling figure, had been following Thingumy and Bob, freezing everything in its path. Moomintroll wakes up from a nightmare, still haunted by the Groke's pursuit. Outside, Moominpappa discovers that the Groke's presence has frozen all the roses, a testament to its icy touch. The family speculates that the Groke is after Thingumy and Bob, who are hiding a mysterious suitcase. Moominmamma attempts to coax information from the secretive duo while bringing them breakfast, but they remain tight-lipped. She learns that the Groke isn't after them, but rather the suitcase they possess, which apparently belonged to the Groke. The Moomin family is concerned, fearing they might be harboring criminals. Moominpappa suggests asking the Groke directly, but Moominmamma quickly dismisses the idea, not wanting the terrifying creature back. They decide to wait for Thingumy and Bob to open up on their own, believing that if they act indifferent, the secret will eventually be revealed. Snorkmaiden, known for her gentle and understanding nature, is chosen to be the one to befriend them and uncover the truth. Snorkmaiden, with Moomintroll accompanying her, visits Thingumy and Bob. She presents them with a beautiful seashell, a gift Moomintroll had given her, which instantly captivates the two small creatures. This act of kindness helps build trust. As Snorkmaiden takes them for a walk, Moomin, Little My, and Moominpappa secretly follow, eager to hear what they reveal. After much gentle persistence, Snorkmaiden finally gets them to admit that the suitcase belongs to them, but its contents belong to the Groke. They confess that the contents are the most beautiful thing in the world, and they are terrified of the Groke's revenge but refuse to give it up. Facing the imminent return of the Groke, Moominmamma devises a plan. When the Groke arrives, Moominmamma bravely confronts it, offering to trade items from her handbag for the suitcase's contents. The Groke, however, is uninterested in her trinkets. In a moment of desperation, Moominmamma offers the beautiful seashell that Moomintroll had given to Snorkmaiden. The Groke accepts the seashell, and in return, promises never to return. Moomintroll is initially upset about his gift being given away, but Moominmamma explains it was necessary. He later finds an identical seashell, ensuring Snorkmaiden won't be disappointed, and the Moomin family is safe once again.