Shardar the powerful king of Brek Zarith, obsessed with his inventions, detains Aaricia, the young wife of Thorgal, and his son Jolan. The latter has strange powers which announce to Shardar the arrival on the one hand of warriors to supplant him but on the other hand a greater danger, a unknown brown only: Thorgal. The latter manages to penetrate the castle of the king and thus gradually discovers all the madness of the sovereign. Accompanied by Aaricia and the little Jolan whom he did not know he will try everything to get to the end of this story.