Dragon Age II Walkthrough: Act 1 : Part 3
Long Way Home
This is the quest you received in the Prologue. Leave town and head for Sundermount. Make your way towards the Dalish camp, fighting the spiders along the way. Give the amulet to the Dalish keeper, who will ask you to take the amulet up to the altar on the mountain. She will have Merrill join you in this journey, and considering the fights ahead you can always use an extra pair of hands. Head together up the mountain and enter the Sundermount Passage. Make your way through the caverns to the mountain graveyard. Reach the altar and complete the ceremony. Then return the amulet to Keeper Marethari down in the Dalish Camp.
The Seal of House Talwain
You should find the seal in the Sundermount Caverns while doing the quest Long Way Home. Deliver it to in Sareth Talwain in Hightown.
Wayward Son
After completing the quest Long Way Home, speak to Arianni in the Elven Alienage in Lowtown to start this quest. Speak to Thrask in the Gallows Courtyard or Vincento in the Lowtown Market during the day. You can speak to both if you wish. Convince any of them to give you more information. With Thrask, you can use diplomacy or have Aveline convince him that he needs the City Guard to help. With Vincento, have either Bethany or yourself (if you are a mage) perform a feat of magic to convince him of your intentions. They will tell you of Samson who knows the location of the Feynriel. Head to Lowtown at night and find Samson. Then make your way to the Docks and enter Arthuris's private docks. After you clear the docks, head to Darktown to confront Danzig, the Slaver. Kill Danzig and get the map of Feynriel's location, then exit the city and head to the Wounded Coast. Make your way to the Slaver Caverns and enter them. Locate where Feynriel is being held. The best way to free him, if you have Varric in your party, is to have Varric convince the captor to let the boy go. Talk to Feynriel and decide whether to send him to the Circle or to the Dalish. Then return to Arianni in Lowtown to inform her of her son's fate.
An Errant Letter
Kill the Abdomination during Wayward Son Quest. Loot it to find a letter. Deliver that letter to Thrask to complete the quest.
Magistrate's Orders
Talk to Magistrate Vanard in Hightown north of the Hightown Estates. He will ask you to apprehend an escaped prisoner. Travel to the abandoned ruins outside the city. After the cutscene, enter the ruined passage to the south. Find Kelder in the caves, and decide whether to kill or spare him. Then return to the Magistrate in Kirkwall to conclude the quest.