Hugo's harmonious existence at home in the Triggi Troll Forest is threatened with extinction because Scylla - the wickedest witch this side of the West - has discovered a book describing the secrets of Iduna's Cave. It is here that the mythical Phoenix Tree grows one apple every 1000 years. And if you are lucky enough to eat the apple you are granted three wishes. Scylla has a deep-hearted wish for ultimate power and eternal beauty. But most of all she despises the trolls, longing for their permanent extinction. So now she has the chance to have all her wishes fulfilled!

The almanac describes how one has to find and learn the magic of Iduna's Sisters to open the sealed cave. Iduna's Sisters are enormous statues hidden at the bottom of the sea. Raising all of Iduna's Sisters to the surface is the key to the cave. Scylla now sends all her faithful cronies to look for the statues and by any dastardly means necessary keep Hugo away from both the statues and her plans. But by chance Hugo learns about Scylla's evil plans and Iduna's Cave. Now Hugo and his friend Fernando must find the mysterious statues, learn the magic, and get to the cave before Scylla. And by any means possible he must stop her from exterminating the trolls from the Triggi Troll Forest forever.