Check the Writing Desk in the Hawke Estate and accept the request from the letter Night Terrors to begin the quest 'Night Terrors' . Head to the Elven Alienage in Lowtown and speak with Arianni. Accept her plea to continue with the quest. After the scene you get a chance to gather a team, but you cannot take Sebastian.
In this part of the Fade you can gain four attribute points for Hawke before actually doing the quest. This requires you to solve a number of puzzles but it is well worth it. See below if you are having troubles figuring them out.
Puzzle #1 - In the room you arrive in is a floating book . The objective is to catch the book but chasing it will not work. Watch the pattern it moves in to stand in a location where it will be, then interact with the book to gain +1 Attribute Point .
Puzzle #2 - The room to the east has a barrel puzzle. The objective is to make the four large barrels be on the bottom and have the three smaller ones on the top -- in under 18 moves. Follow the steps below to finish the puzzle in 14 moves total. If you fail to do the task you lose the chance to ever get the point and must fight a group of spirits.
Puzzle #3 - You can find this puzzle in another eastern room. The objective is to have stacks of red barrels like the ones on the side of the room. Accomplish this task in under 18 moves to receive +2 Attribute Points , fail and fight more demons. The steps below will complete the puzzle in 16 moves total.
With the puzzles behind you, enter the main area to the south. Here you can strike a deal with the Sloth Demon, Torpor or choose to fight him. The former involves corrupting Feynriel and letting Torpor control him, the latter will let you choose Feynriel's fate (base on your actions). Torpor offers Power ( 4 Attribute Points ), Knowledge ( one Talent Point ), or Magic ( Torpor's Barrier Rune ) -- know that siding with Torpor while having Anders in the party results in a fight where Anders is dismissed from the Fade.
In this place Hawke's actions influence Feynriel's mental state. Doing things that are tempting and morally/ethically wrong will result in instability while doing the "right" thing will result in high stability. Enter Feynriel's Desires and watch the scene, your answers affect Feynriel's stability.
- Tell Feynriel to go with his Father for a high increase in **INSTABILITY** .
- Tell Feynriel that he is in the Fade with a Demon for a low increase to **INSTABILITY** .
- Tell Feynriel that his Father doesn't love him to gain **STABILITY** .
Return to the central area and enter Feynriel's Pride. Check the southern room for a book called Beyond the Veil: Spirits and Demons then continue east to another scene.
- Tell Feynriel to accept his Destiny for a high increase in **INSTABILITY** .
- Tell Feynriel that it's a Demon results in a low increase in **INSTABILITY** .
- Tell Feynriel to reject his Destiny for a gain in **STABILITY** .
Here you will find Torpor if you made a deal with him. If Feynriel is stable then Torpor will take over, but if he is unstable Torpor will attack. You can always go back on your promise but you lose out on the reward Torpor offered. If you killed Torpor already then Feynriel will leave the Fade if stable or ask for a mercy killing if unstable.
After the quest completes any member that was tricked by a Demon will want to talk to Hawke. Talk it out with the party but know that you can sway Friendship or Rivalry based on your words.