There's only one very simple puzzle to solve here. Left of where a section of the floor is missing you find a gold dome. Open the dome and click the symbol inside to raise the floor.
 
 
 

THE UNKNOWN AMULET

During the closing scenes you see Arkampus among Durad's band of followers. Remember him? When you released him from the cell an Unknown Amulet mysteriously appeared in your inventory. From what Durad says about you 'being easy to find', the Unknown Amulet must be some sort of tracking device planted on you by Arkampus.