Ororéa invite Spirou and Fantasio to a magicians congress in Brittany. There, they met the Ankou, the Death lackey in local folklore. The latter protest that the local nuclear power plant is going to provoke an excessive mortality rate, and thus bring extra work for him. Turns out that at said power plant, the Thyrinium 2000, a super powerful radioactive product, is developed there. Gangsters are trying to put their hands on it, and it includes kidnapping Fantasio in exchange for the Thyrinium.
Tropes associated with this story include:
- Anti-Villain: The Ankou. He does not take people's lives maliciously-he's just doing his job.
- Arbitrary Skepticism: Fantasio stubbornly refuses to believe that he's dealing with a supernatural creature.
- Author Tract: Most of Fournier's run had a strong ecological vibe, so it's not a surprise that the album criticizes civilian nuclear power production for "defiling" the folklorish lands of Brittany.
- Grim Reaper: Spirou and Fantasio get to meet the eponymous collector of souls. Because of their unfamiliarity with Breton folklore, they aren't nearly as scared as they ought to be.
- Stealth Hi/Bye: The Ankou does it all the time, making the heroes rather jumpy.
