Dragon Age 2 - Blackpowder Courtesy is a main plot quest which serves as somewhat of a continuation to the Blackpowder Promise quest from Act 1. In this walkthrough, players will once again meet with the Qunari, in attempts to retrieve their stolen supply of poisonous gas, before it can be used to harm people in the city. The quest ends with a relatively easy fight against of a group of mercenaries and their elven leader.

1. You will automatically receive this quest in a cutscene at the beginning of Act 2.
2. After the cutscene, visit the Qunari leader, Arishok, at the Docks’ Qunari Compound.
3. Speak with the Qunari at the entrance to the Compound, and then enter to go speak with Arishok.
4. Head to Darktown and follow the quest arrow.
5. Speak with Coterie.
6. Follow the new quest arrow to the Smuggler’s Cut passageway nearby.
7. Move through the tunnels. You will encounter some dwarven resistance, but nothing major.
8. Speak with Javaris.
9. You can decide to kill or spare Javaris.
10. Leave the area, and head back to the City to find the Elf. Choose the “Side Alley” location near Lowtown.
11. Pick up the steel piece from the ground, and start closing the barrels. The pieces are hard to mouse over, so don't get frustrated. You will have to do this a couple of times, and fight mercenaries in between each barrel.
12. Kill the mercenaries. The fights are aren't too difficult, just make sure to leave any tough mercs (like the Commander) to last.
13. Continue picking up the steel and closing barrels.
14. After the small cutscene, focus down the elf mercenary leader before killing her weaker minions.
15. Once you’re done killing the mercs and their leader report back to Arishok at the Docks.
16. Return to the Viscount at the Keep and speak with the Viscount to finish the quest.