Location: At the beginning of the game, in the main courtyard.
Rescue Reward: Ancient Chalice
From the Manual: Father Aville is the Patterson’s family priest, and has with time gotten very close to the family. He has learned a lot of the occult and other esoteric topics through his specialized work within the Church. He’s been asked to wed the couple.
Father Aville is the first character you encounter in the game. Shortly after you step into the castle courtyard, you'll see him being rather rudely thrown out of one of the East Wing's top floor windows. He'll give you the Crucifix as soon as you meet him, but he's seriously injured and will require medical healing before you can bring him back to the Sanctuary. In order to save Father Aville, you must rescue Dr. Amersfield and bring him to the injured priest before 30 minutes goes by. If you take too long, the good Father dies from his wounds. Save Aville and bring him b
ack to the Sanctuary, and he'll reward you with a chalice that you can fill with holy water and use as a powerful weapon. The chalice is the most powerful weapon in the game, and rescuing Father Aville really isn't all that hard, so you really should do your best to help him. Whether or not you save him, you can find pages of Aville's diary throughout the castle that describe some of the enemies you face and exactly what's going on.
NOTE: Unlike most of your relatives, Father Aville doesn't have a recoil animation. So if he gets hit, there's no indication that he's taking damage until he kneels over and dies. Since Aville is located in the Main Courtyard which is devoid of enemies, this isn't really an issue.