Obey Lacarat's instructions

1.  Steal the Orb of the Moon from the Tower to remove the enchanted protection from Dacorault.
Go to the East end of the North corridor and down the main stairs.  The metal door facing you across the hall is the entrance to the catacombs.  Go in, descend the several flights of stairs, then follow the passage. Use the key to unlock the second door you come to.

Head East through the catacombs, and then North past the statue - the double metal doors ahead are the main entrance to the cathedral.  You can open these doors and then creep up the steps on either side, but you have to be very careful.

An easier option is to turn East opposite the cemetery gates towards the religious symbol (a T with a truncated circle above), skirt it to the left then go North.  You can either rope up to the balcony, go in and turn right up the steps, or go through the metal door and on to the end of the passage, climb the ladder into the boxroom and go out of the door.

Now go West, through the metal door and up the steps as far as you can.  Climb the ladder on the right and open the door with the Tower key.  The Orb of the Moon is suspended in the structure in the centre of the chamber.  Walk along one of the supports and grab it.


2.  Avenge Lacatar's death by slaying Dacorault.
Retrace your steps all the way back to the balcony doorway on the East side and look down into the cathedral.  There are three mages on the altar plinth.  Dacorault is the man in the centre.   Shoot him with a broadhead arrow (or a fire arrow if you have one).