Darkness Returns Darkness Returns is a quest available in . Walkthrough . To complete this quest , the Dragonborn must take the Pilgrim ' s Path to the Twilight Sepulcher in order to put the Skeleton Key back where it belongs . As the Sepulcher is entered , the ghost of Gallus Desidenius , the Nightingale murdered by Mercer Frey , is encountered . He warns the Dragonborn that , because the Key is missing , the other ghosts have been corrupted and are now hostile . When asked about the obstacles to reaching the Ebonmere Lock , he advises to look for a journal that belonged to another adventurer , Nystrom . His skeleton is to the east of Gallus . Nystrom ' s journal holds some clues to the trials : " " Shadows of their former selves , sentinels of the dark . They wander ever more and deal swift death to defilers . " " " " Above all they stand , vigilance everlasting . Beholden the murk yet contentious of the glow . " " " " Offer what She desires most , but reject the material . For her greatest want is that which cannot be seen , felt or carried . " " " " Direct and yet indirect . The path to salvation a route of cunning with fortune betraying the foolish . " " " " The journey is complete , the Empress ' s embrace awaits the fallen . Hesitate not if you wish to gift her your eternal devotion . " " Nystrom also says that the man who gave him the clues mumbled nonsensical phrases like " night is the new day " and how he was the " ghost of the sun . " First Trial - Sentinels . " " Shadows of their former selves , sentinels of the dark . They wander ever more and deal swift death to defilers . " " The first trial is facing the shadows of their former selves , sentinels of the dark - Nightingale ghosts , hostile and powerful . Either sneak past or kill them . If they are killed , there is valuable loot on both sides of this area . When entering the first trials room , it is relatively easy to sneak attack the Nightingale Sentinel with a bow as they are directly in front of the Dragonborn when they enter . Then they can continue on to the next trial or , in the chance of receiving more loot , kill the other Sentinels . In the room on the left , with the alchemy lab , there is a desk . A button behind this desk opens a secret door in the same room revealing moderate loot . Second Trial - Light versus Dark . " " Above all they stand , vigilance everlasting . Beholden the murk yet contentious of the glow . " " For the second trial , night is the new day : avoid the light and stay on the darkest path . One can enter sneak and go through the mist . Standing will cause large amounts of damage . Watch for trip wires when going up the staircases . During this trial there are no enemies . Candlelight and Magelight spells can also help if having trouble finding the way around , as their own lights aren ' t harmful in this area . Third Trial - Hidden Door . " " Offer what She desires most , but reject the material . For her greatest want is that which cannot be seen , felt or carried . " " For the third trial , in the room with the statue and a dead bandit lying in front of it , there are two large sconces to either side of the statue . To the left of the left hand sconce there is a chain , and at the right hand side of the right sconce there is a second chain . Pull the two chains to put out the lights of the sconces , so giving her ( Nocturnal ) what she desires most ( darkness ) . The door behind the statue will then open . Fourth Trial - Sentinels vs . Traps . " " Direct and yet indirect . The path to salvation a route of cunning with fortune betraying the foolish . " " For the fourth trial , there are some options : After looting the entire area , proceed north to Twilight Sepulcher - Inner Sanctum . Very soon , there is a point of no return ; be sure you have looted everything you want before proceeding . Fifth Trial - Inner Sanctum . " " The journey is complete , the Empress ' s embrace awaits the fallen . Hesitate not if you wish to gift her your eternal devotion . " " As you proceed through the Twilight Sepulcher - Inner Sanctum , you will come to a steep pit . This is the point of no return ; when you are done here , the first part of the Twilight Sepulcher will be sealed . Fall into the pit and search Anders ' skeleton ; read the message . Wait a few seconds until the Skeleton Key reacts . The ground will disappear and you will fall . When you land , place the Skeleton Key into the Ebonmere Lock . That will summon Nocturnal , who will bid the Dragonborn to drink from the Ebonmere , " for this is where the Agent of Nocturnal is born . " Then speak to Karliah , and she explains the choice that must be made between the Agent of Strife , Subterfuge and Stealth . To pick one , step on the corresponding moon . They give greater Powers , usable once a day only . The Dragonborn can later choose to change the chosen power after a day so there is little pressure in choosing the best ability . Next , talk to Karliah . After Karliah is spoken to , Gallus ' ghost will appear and they will speak shortly before he goes to Evergloam . Karliah , then , goes back to Nightingale Hall . The Dragonborn can then leave through the southern portal . Powers . Nightingale of Shadows Nightingale Subterfuge Nightingale Strife