Soul Cairn ( Dawnguard ) The Soul Cairn is a location in . It is a plane of Oblivion inhabited by souls and undead . It can be accessed via a portal in Castle Volkihar during , and after , the quest " Chasing Echoes . " Background . When a soul is trapped in a Black Soul Gem and its energy used to power an enchantment , the remnant — the soul itself — is sent to the Soul Cairn . It is a place devoid of ( faunal ) life — the only beings that exist there are souls , undead and the rulers of the realm , the Ideal Masters . The Ideal Masters are enigmatic entities that lord over the Soul Cairn , controlling every aspect of its being . It is believed that the Soul Cairn exists so that the Ideal Masters can collect souls and feed on them ; some hypotheses even suggest they use the souls as a form of currency to an even higher power . The Soul Cairn is also home to powerful undead beings , which are highly sought after by necromancers . Souls are sent to the Soul Cairn by necromancers who wish to summon these undead , but in order to do so they must travel to the realm in person to finalize the deal with the Ideal Masters . They are often tricked , and many become trapped as harvested souls . Geography . The landscape of the Soul Cairn is barren and dry , with only dead trees and bushes scattered throughout the realm , as well as plant - like growths known as Soul Husk s . The sky is perpetually bleak and cloudy , and lightning strikes constantly throughout the realm . There is no sun in the sky , but instead a single moon and a huge black circular void . Numerous buildings and altars can be found throughout the land , alongside mysterious upright stones and circular crystalline structures . The crystal circles will replenish the health of any being that stands in them , although they will quickly dim and become inert after use . In the tallest towers , the uppermost sections are composed of blocks suspended in midair , rotating around the tower and emitting a purple light . The realm is partitioned by an enormous fortified wall that divides the landscape , though it is unknown why . Magical barriers also block off certain areas . Soul Fissures . There are luminescent cracks in the ground throughout the Cairn . Interacting with one will fill the largest empty soul gem on hand , but soul fissures will not fill the Black Star or Azura ' s Star . Crystalline structures . Scattered across the Cairn are a number of floating purple crystals that resemble giant soul gems . Approaching these will drain the health of any living being that gets too close . Eating a Soul Husk or Soul Husk Extract , however , will counter the drain for a short time . Lightning Attractor . There are four Lightning Attractors located in the Soul Cairn . Activate these by using Grand Soul Gems or Greater Soul Gems . Lightning will strike the rod , and Mistmen , Bonemen , and Wrathmen will appear . Also , the soul gem will be replaced by a Black Soul Gem . After being struck , the rod will slide into the orifice and the Lightning Attractor cannot be activated a second time . Locked rooms . There are rooms scattered about the Soul Cairn that have metal poles blocking their entrances . These can be unlocked by shooting both of the glowing blue orbs in the obelisks nearby with spells or arrows . Sub - locations . Reaper ' s Lair . While inside the Soul Cairn , if the Dragonborn turns right after going through the stone wall and follows the barrier , the Reaper ' s Lair will be found just past one of the large towers with floating blocks and swirling energies at the top ( It is not the structure where there is a lantern on the ground in the alcove ; rather the next building to the east of this one ) . Inside lies the Reaper Shard Receptacle , which is activated by placing three Reaper Gem Fragment s in the receptacle . These fragments are located in chests beneath three of the giant floating soul gems which drain health . Lightning frequently strikes the center of the room . Putting three shards in the receptacle summons The Reaper , who attacks . If one goes into no - clip while inside the lair , they may notice three paddleboats side - by - side floating over nothing . Note : If one of the alternate methods to spawn the Reaper is used , it will not show if the three Reaper Gem Fragments are used ( confirmed on PS3 ) . Boneyard . The Boneyard is accessible after killing the three Keepers . Valerica is trapped here along with one of the three Elder Scrolls . Shortly after the Dragonborn enters the Boneyard , Durnehviir will attack . Quests . Chasing Echoes . Serana ' s mother , Valerica , is found here . She offers an Elder Scroll to the Dragonborn if the Keepers located at the tallest spires in the Soul Cairn are defeated . She warns that a fearsome Dragon named Durnehviir may take notice of the Keepers ' demise . Once all of the Keepers have been killed , the wall that blocks access to the castle disappears . After entering the Boneyard , Durnehviir will appear and attempt to kill the Dragonborn . Defeat him and speak with Valerica , who will lead the player to the Elder Scroll . After acquiring the Elder Scroll and exiting the Boneyard , Durnehviir will be found waiting on a broken structure . After conversing with him , he teaches the Dragonborn a shout to call him from the Soul Cairn . Impatience of a Saint . The Dragonborn can interact with the soul of Jiub in the northeast section of the Soul Cairn . Jiub explains that he wants to write the second volume of his opus , but he has lost the pages to his first volume and requires them to continue writing . There are ten pages in total , scattered across the barren landscape of the Soul Cairn . Find Arvak ' s Skull . The Dragonborn can also complete a side quest to free an undead skeletal horse named Arvak . This mount can then be summoned at will in either Nirn or the Soul Cairn . Arvak ' s Skull can be found under a glowing pavilion near the big castle . Returning the Skull to its owner will reward the Dragonborn with the Summon Arvak spell . Soul Husk Hunt . There is a soul , named Morven Stroud , in the northern section , directly east of the dividing wall . Speak to him and he will ask for twenty - five soul husks in return for the opportunity to " see his wares " . For every twenty - five soul husks the Dragonborn brings to him , they receive the opportunity to trade for a random sword , battleaxe , light armor , heavy armor , or spell tome . This quest is repeatable as soul husks respawn . All of the items he has to offer are enchanted . A glowing pit portal to the right of Morven Stroud will teleport the Dragonborn to the top of a building . Look to the building with the obelisks with glowing orbs , there is a spot to jump down to get a hidden chest .