Tier 1: Make Your Way to The Nearby Temple
When you get to the temple and click on the Colossal Temple Door, you will find out that it is locked. Not only that, but now the sarcophaguses are opening and mummies are stepping out to attack you. After you take care of a few mummies, only 1 Sarcophagus will remain. When it opens, a Master of the Guards will step out and take a few swings at you. Kill him and loot the Temple Key that will appear on the floor where he died.
Tier 2: Entice The Head Scribe to Show Himself
Upon entering the Scribe room, you need to investigate it and make the Head Scribe come out of hiding. To accomplish this, go and click on a Ancient Scribe Tablet and read it.
Next collect some Letters meant for Akhemahen and take them over to the pyre in the center of the room. Setting them aflame will certainly entice the Head Scribe to show himself.
When the Head Scribe appears after you burn the letters, take him out. There is nothing special about the fight.
When the Scribe dies, he drops a Tablet. Examine it to read the Orders from Rib-Hadda.
When you enter, you should notice that there is a space on the right hand side of the door that needs to key fragments. These are needed to open the door. The first piece comes from Rasul The Messenger. The key fragment will drop onto the floor once he is dead. Pick it up and look around for Messenger of Rib-Hadda, a big guy with an axe. He drops the other key fragment.
Update courtesy of Hologramx:
The door switch consists of 4 parts. Looks like it is random and you may need 3 or 4 pieces to fill in the hole to open the door. Every mob in that area drops a random piece on the ground that you need to loot.
Tier 4: Defeat Rib-Hadda
Easy encounter as long as you know the trick. In order to damage him, you need to break the four statues that are channeling him. You need to kill the 4 statues. You will be stunned when you hit them but you will gain some heal when you destroy each one.
See our complete list of guides, solutions and walkthroughs by clicking here.