First I apologize for english mistakes, not my native language
I first runned after seeing agrippa for the first time, and in the room just before the presbytorium I found the fresh meat (the thing you've to feed the Kaernk with). I got to the place where you need to rebuild the orb (without being kidnapped because I had'nt any orb fragment yet). Then I understood and found the orb fragments, but just before the transept, I found a well, I attached the meat and managed to get the bone.
Some time after, I was kidnapped and sent to jail. I found a basket in it. Some time after you get in a room with a well. I already had the bone, but tried to attach the basket. It worked and the basket was destroyed. What is the goal of the basket ? This is the first useless item I saw in Amnesia.
And another question, in the room before the presbytorium (where you found the meat) they are some jails at the first floor, in one (where you ear someone crying in) when you enter, lot of lights are turned off and some monsters are coming. What's the story of that little room (if someone knows it) ?
And another question (again :p ) When you need to cut the Agrippa's head, you find the saw in a room. In this room there's a door that you can't open. Is there a way to open it ?
1. You use water from the basket to get a key for a prison entrance, I believe.
2. There is no "story", actually. It's just Shadow kills all prisoners (who is still alvie).
3. Hmm... since the elevator is broken, I believe this is an escape path for "Revenge" ending.
Oh thank you for these answers, I understand a little more :p
Spoiler below!
Again a question, do you think "monsters" are still in the castle in the revenge ending ? Do you think they are killed by the shadow ? I don't know, want opinion of other people.
I think they are not, since we see Daniel walking through the areas that had monsters in them without caring. (The water monster long hallway chase, the sewers)