Ensure you take part in this quest if you want to keep the Temple of Light active when you return from the Spire, though completionists should note that you will want to take part in The Temple of Shadows before this, as there are hidden items in the temple that are only accessible via this quest (see below). The monks will inform you, upon returning to the Temple to initiate the quest that the water supply is being poisoned, the one used in the crucial ritual we took part in with Hammer. Head back to Wellspring Cave in a deja-vu moment and systematically clear out all the enemies within.
There will be a body of Shadow Worshippers and a Monk in each of the three fountain rooms we were in with Hammer, so clear them all out to bring the head of the Shadow Worshippers Cornelius Grim out of the woodwork along with his army of Hollow Men. Take him out to keep the temple in good order and receive the Temple of Light Seal and 750 renown.
For the bad option, The Oakfield Massacre, you first must have made sacrifices to the Temple of Shadows, so we'll go over the quest involved with that first.
