Jolan has agreed to leave his family and serve Manthor, after he saved Thorgal's life. The mysterious mage has promised him an exceptional destiny - if, that is, the young man proves worthy of it. So begins a series of trials during which Jolan, on his own at first, will meet four other youngsters. They, too, have unusual powers. They, too, are on their way to Manthor's castle. Will they be allies, or enemies?