Melle and his family are staying with an old friend of dad, who is a biologist in the Alps. In the middle of the night, Melle's little sister Limoni wakes up in a panic. Where is her backpack? And more importantly, where is her own Gorgel, Belia? That is the beginning of a blood-curdling adventure in which the trail leads to the glacier that is slowly melting now that it is getting warmer. Melle, Bobba and Limoni get to know marmots, birds of prey, Mountain Gorgels and Vomiters. They are helped by Katja, who knows all about the dangers of the mountains...