Darko's formation ended, it was necessary to leave Eleven Racines, Master Og, and resume the search for the Titans. Darko does not know that the terrible pontiff Xarchias is no longer, but that he has left room for an even more appalling threat. More than ever, Opale needs the return of the Titans. On their track, Darko, Urfold, Sleilo and Tara are now trying to cross the Dorsale, the chain of mountains that cuts the world and goes to the sky. Indeed, they find traces of Cohars, the ancestor of Darko...