While Jolan and his companions finally learn from Manthor what their grand destiny will be, Thorgal is still on the trail of the men who kidnapped his other son, Aniel. Along with jolly mercenary Petrov, he sails down a frozen river aboard a Blade Ship - a trade vessel equipped with heavy metal blades to break the ice. The journey is fraught with dangers - storms, raiders, spies, wild animals... and a group of shipwrecked Vikings looking for a mysterious chest...