No monsters for Chancel Ambush?

[Cranky Old Man]

Okay well, which door? The one to the chancel? Yes i am standing inside. Hoping and wishing for the grunts to carry me away to somewhere horrifying. But they wont. Ive looted and searched the entire chancel. When i went in before (when i first met agrippa) There were monsters so I ran back out but now they are gone. i DO NOT want to play the game over again

Okay, so I'm assuming the following:
1. You had collected all the six orb pieces.
2. You then went inside the Chancel, triggering the ambush.
3. You then found that the door back had NOT locked behind you for some reason.
4. You exited the Chancel, and then later went back in.
5. Now the ambush is triggering, locking the door behind you, but the monsters have all been "used up", so you're stuck there.

I don't know how you managed to escape the ambush the first time, but you can always load an earlier save, from before you gathered all the six orb pieces or triggered the ambush the first time.