Ritual of Dementia Sheogorath wants the Hero to replace one of the aristocracy of his kingdom : either Lady Syl , Duchess of Dementia ; or Lord Thadon , Duke of Mania . Taking sides . Note : " This is the point at which one must chose which Duke / Duchess to replace . Though one can pick either side and still complete the Main Quest , the choice will have certain consequences . " If one picks Dementia , this will start the Ritual of Dementia . Walkthrough . After speaking with Sheogorath , talk to both priests . They can explain Arden Sul ' s background . Both sides claim Arden - Sul was their duke , though their stories of his final day are wildly different . If one chose to take the throne of Lady Syl , speak to a resident of Crucible such as Gloorolros . Once they increase their disposition , they will tell them that Syl is rarely seen in public and relies on her aides Kithlan and Anya Herrick . Access to House of Dementia . Speak to Kithlan first and raise his disposition enough and he will give them a key that opens any door in the House of Dementia . If one raises Anya ' s disposition enough , she will also help by distracting two of the guards . Let her enter the Private Gardens first . They will have to fight two Dark Seducers before one can enter Syl ' s private chambers . There her dead body is on her bed . However , Kithlan jogs up and tells them that the dead body is merely a decoy , and they must follow her into a secret passage in the Gardens . Xirethard . The secret door is in the Gardens , next to Syl ' s private quarters , hidden behind a bust of Sheogorath . Activate it and it will slide back to reveal a passage down to Xirethard , an ancient ruin . It is a heavily trapped ruin . When inside watch out for a network of passageways guarded by drain - health - spitting statues . The map will be invaluable for navigating this section . A switch at the end will turn off the statues , allowing time to explore the halls , where potions and gold lie . Fight past some Dark Seducers and into Xirethard Depths . There will be two Seducers in a circular room . Kill them and look for a switch on the north side of the room , at the base of a bust . Follow the hallway around until one get to a long room with a staircase on the south side . A single Seducer will be guarding the top of the stairs . Behind her , a doorway leads to another room . Syl is in this room and , if the innumerable traps and guards weren ' t an indication , will be difficult to take down . No longer wearing her regal gown , Syl is now clad in Seducer armour and packing real heat in the form of Nerveshatter . Kill her and take her heart . Don ' t forget to look for a chest with leveled loot in the room . On the east side of the great room is door to Xirethard , Subterrane . This level is filled with undead . Fight them all the way through , taking care to avoid statues that shoot spells and collapsing ceilings . Sacellum . Once outside of Xirethard , go back to Sacellum Arden - Sul . Put Syl ' s Heart on the altar . It will glow for a few seconds and then disappear into a bluish - green burst . Arctus , High Priest of Dementia , will declare the Hero Duke / Duchess of Dementia . Speak to Sheogorath and he will congratulate them on their new title . Suddenly , Thadon bursts into the temple , devastated by Syl ' s death and worried about the Greymarch . He says he will leave Sheogorath ' s side and serve Jyggalag as a Priest of Order . Thadon also says that the Fringe has been taken over by the forces of Order . Speak to Sheogorath again and he says that he is pleased by Thadon ' s treachery , as this has never happened before , and new is good . He will give the Hero the Ring of Lordship . He also thinks that Thadon is correct about the Fringe being lost and sends them to investigate . At this point , they also have full use of the Duchess ' Private Quarters . Take anything one wants , sleep in the bed and store anything in any of the containers . Every container in the Quarters is safe and will not reset . This ends your current quest and begins the next : Retaking the Fringe .