Dragon Age 2 - On the Loose is the first main quest in Act 3. For this walkthrough, players will track down 3 dangerous mage apostates in Kirkwall, to either save them from the Templars' persecution or kill them if they turn hostile.

1. Head into your estate, and read the letter from the Knight-Commander. Accept the letter, and go meet her in the Gallows.
2. Make your way to the quest location inside the Templar area.
3. Speak to Elsa.
4. Ask her about all 3 apostates.
5. Start out in Hightown. Choose night, and go to the quest location.
6. Speak with Emile’s parents. They will tell you go to find him at the Hanged Man during daytime; go and do so.
7. Once you’re done with Emile, head out of the Tavern and go to the Elf Alienage to speak with Nyssa.
8. Speak with Walter in Darktown.
9. Go into the Sewer Passage marked nearby.
10. When you reach the spike trap, run through it, and pull the lever ahead so that your party can pass through.
11. The Evelina fight is pretty simple. Just focus her down quickly, and kill the Shades in between the times she disappears.
12. Go back to the Alienage on Lowtown at night, to confront Huon.
13. Kill Huon. Make sure to target him down quickly as he has powerful spells.
14. Report back to  Meredith at the Templar’s Hall in the Gallows.
15. Head back to your estate and read/accept all your letters.