Melle and his family are staying with an old friend of Dad's, who is a biologist in the Alps. In the middle of the night, Melle's sister Limoni wakes up in a panic. Where's her backpack? And more importantly, where is her own Gorgel, Belia? That's the start of a blood-curdling adventure in which the trail leads to the glacier that is slowly starting to melt as it gets warmer. Melle, Bobba and Limoni are introduced to murmur bulls, birds of prey, Berggorgels and Kotsbalgers. They are helped by Katja, who knows all about the dangers of the mountains...