In a supernatural storm and stranded on a glacial ice pack, Thorgal discovers that the Fimbulvinter, the legendary great winter announcing the end of the world, is near. To save his own and stop this threat, he will have to venture to the heart of the kingdom of giants and face the flames of Muspelheim. In the company of mysterious and dangerous allies like the magician Vakva, daughter of the Queen-Sorcier of the Ile du Givre, he starts a perilous quest to steal the Magic Fire capable of repelling the eternal winter. The future of the worlds is now in Thorgal's hands.