Hi. Sorry about this.
Here are the steps you'll need to proceed.
1. In the library room, talk to a priest looking at a bookshelf. He'll tell you about an odd guard upstairs.
2. In the blacksmith room, talk to the purple haired boy in the lower right corner. He'll tell you about a hidden room.
3. Speak to the guard upstairs after that. Henry will take note of how odd he is.
4. Speak to the maid in the kitchen to get food for said guard.
5. Speak to the guard again, and he'll get lost.
6. Go into the room behind him to find a text book detailing what's going on in the church.
7. Go into the empty room with two statues and a flat podium in between it and a hatch will open revealing a pair of stairs.
If you need me to provide pictures to these specific characters do let me know and I'll ask you to hit me up and discord to show everything.