Dragon Age 2 Quest Reference: Act 1 - Main Plot - Enemies Among Us

Requires: Tranquility

Talk to Macha in front of the Chantry in Hightown to get this quest. She'll ask you to find her brother Keran, who recently disappeared after joining the templars. Follow your minimap prompts to proceed after this. You'll face your first battle at Wilmod's Camp, when he transforms into a demon. This will lead you to the Blooming Rose. Be sure to get a mage before going there.

Sparing Indunna after speaking with her will unlock Forbidden Knowledge, although there are other ways of unlocking it if you don't spare her. Go to Darktown at night and follow your minimap to proceed. Be sure to loot the bodies after the battle in the Sanctuary, you'll find the book to unlock the Grimoire of the Apprentice quest a little before the exit, this is the only place you'll find the book and it's not available after this.

After you find Keran return to speak with Cullen. If you select "Keran is fine" to persuade him to let Keran stay in the templars, you'll get a friendship bonus with Anders, four Sovereigns and unlock the quest How to Frame a Templar. If he's expelled from the templars, you'll unlock A Debt in the Family instead.