The narrator tells us that Caius has been attacked by a beast. It's not Caius who's been attacked, but the beast's name is "Caius" . Caius explains that the wine that was delivered to his bride-to-be was poisoned with poisonous fruits. He's put in a system to prevent him from becoming king again. The reason for this is that the people want Caius to have more power than he does. If Caius loses his bride before they get married, he'll lose his right to rule again. So the reason they came here is to keep him away from danger.