The quest is started by examining an "Ill Fated Cleric Journal" which is a rare drop from the Agony. The Agony (-1900, 650) is a fairly rare spawn that wanders by the lake near the entrance to the Temple of Cazic-Thule in Feerrott.

Map of the basement of Cazic Thule. We just killed the Torturer. Orange dots are Terrorfiend spawns.
Zone markers are the Sanctum of Fear

1. After inspecting the journal you are instructed to kill 40 lizardmen in Temple of Cazic-Thule.

2. Now you must then kill four named spawns also in the Temple of Cazic-Thule:

One of the four named

1) Kaxor the Cenobite - East platform on top of the big temple.
2) Hukulan the Despoiler - Up top before the pyramids between the stone wall partitions.
3) Tzugaax the Torturer - Downstairs in the Torturer Area (-51, 0).
4) Xilarga The Tae Ew Champion - West platform on top of the big temple.

3. You are then instructed to find the Fountain of Fear which is the waterfall at the back of the large temple.

4. Once you complete the above step a one hour timer starts. You have one hour to find the Basin of Ba'Kur in Cazic Thule (65, 0). To get to it you must enter the tunnels near the zone in, and after passing the GlareLordroom, turn to the left. The room after the Thulian Terrorfiend is the basin.

5. Now you must kill Thulian Terrorfiends until you obtain an uncommon key.

The Keeper!

6. After finding the key you must head to a special instanced version of the Sanctum of Fear. Inside you will find a small room with four totems. Right clicking a totem will spawn four mobs or the Gorfuzod the Keeper.

7. After killing the Gorfuzod the Keeper you will receive the Screaming Mace: