From publisher blurb:
This adventure follows on from The Heresiarch of Troyes. The spirit, still in the body of the leper Jacques Taillebois, escaped from the Chateau du Paynes via the secret tunnel. Instead of returning to Troyes, the Joyous One set off for the coast.
The Joyous One needs Magic Points to survive. In Troyes, it was able to feed off its cult. It created the new Heresiarch to provide it with a constant supply of food but the characters foiled that scheme. It can still survive on the vestiges of the cult and those it seduces on the road but the more damage the characters do to its cult, the more desperate the spirit becomes. If the characters fail to complete any of the adventures along the way, the final battle against the Joyous One will be much harder.