Finish the quest A Friend in the Guard and then talk to Aveline about a potential job. Aveline will inform Hawke that she has information about a possible caravan raid and needs Hawke's help to stop the raiders.
Go to the Sundermount Ambush Site with Aveline in the party. Once there, you might want to fight your way to the southwestern area of the map. This is the one and only time to visit this location so make sure to strip it of loot and coins.
Once the main ambush site is reached, try to use a ranged attacker, like Varric, to get the ambushers attention and then pull back to where your party is. The reason for this is to avoid the traps and of course to gain the XP when a rogue disarms them after the fight.
Once the area has been searched and all loot and enemies is dealt with, go back to the barracks in the Viscount's Keep so Aveline can report back to Captain Jeven. Jeven will criticize Aveline for her actions, but Guardsman Brennan thanks Aveline for keeping her safe. Brennan also informs them that her satchel was particularly heavy that night, and that the satchel has been passed to Guardsman Donnic for the night. Check out the Duty Roster to see Guardsman Donnic's patrol before heading back out toward Lowtown (Night).
In Lowtown, follow the map marker to the location of Guardsman Donnic and deal with his attackers for some loot and XP. After rescuing Donnic, an aggressive response will yield Varric: rivalry (+5), if he is in the party. A witty response will yield Varric: friendship (+5). If Isabela is in your party, she will offer a brief comment regarding the contents of the satchel. Neither the quest marker nor guardsman Donnic will appear unless you have Aveline in your party.
Once done, head back to the Viscount's Keep to finish this quest.
- Aveline is named Captain of the Guard.
- 400 XP (quest completion).
- Once Aveline is named Captain of the Guard, you can talk to her after leaving the Captain's office. Depending on the final dialogue choice during that conversation you will either receive Aveline: friendship (+10) or, if you choose the rude response, Aveline: rivalry (+10).
- If you are seeking the Supplier achievement, be sure to grab the Elfroot at the Sundermount Ambush Site, on the west side of the looping southern trail.