Received from: Erlina [Denerim - Arl Eamon's estate]
Description: You will be allowed to start this mission soon after one of the main quests of the game (The Landsmeet) has begun. Don't exit arl Eamon's estate. Instead proceed to Eamon's office (M71, 2) where you'll have a chance to talk to arl himself and to one of the servants of queen Anora. You'll find out that the queen has been kidnapped and that is being held in Howe's mansion. Your job will be to rescue her. Leave Eamon's mansion by heading back to [Denerim - Market district] and then choose [Denerim - Arl of Denerim's Estate - Exterior] from the city map.
Once you've arrived at the estate grounds (M72, 1) make a few steps forward and you'll find out that you can get inside the mansion using the side door and to reach it you must start moving clockwise (M72, 2). Be careful, because at least one group of guards will stop you along the way. Eliminating them shouldn't be a big problem as long as you're careful. After you've reached a small garden (M72, 3) Erlina will stop you and tell you her plan. Notice that your team members are now wearing disguise and they should stay that way. Don't worry about them not being able to use their standard items, because this is only a temporary status.
There are two ways for you to gain access to the mansion - you can follow Erlina's instructions by hiding in the bushes (M72, 4) or you can ignore the possibility of using a disguise and attack the guards. I would recommend playing it safe, because it'll be much easier to reach the queen without every guard attacking you on sight. Once the guards have been distracted or killed click on the door they were guarding (M72, 5) to travel to [Denerim - Arl of Denerim's Estate - Interior] (M73, 1).
If you're still using a disguise you'll have to be extra careful, because Howe's men will be well trained and there's going to be a lot of them in the mansion. The largest group can be found in the dining room (M73, 2) and if you play it safe they won't even bother you (otherwise you would have to spend a lot of time trying to defeat them). Keep heading north until you find the chamber where the queen is being held (M73, 3). You'll find that the door is magically protected, so you'll have to figure out a way to break the spell.
Start off by heading east (M73, 4). Avoid entering one of the northern rooms, because after finding a guard who's having a good time with one of the servants you would raise an alarm. Instead try breaking into a small vault located at the other end of the main corridor (southern wall). Thankfully even if you fail in opening a door now you'll get the key to it eventually. The next area is the bedroom (M73, 5) and you should open a chest here to collect documents of the Grey Wardens.
Once you've entered the next room you'll automatically trigger a cut-scene and you'll meet Riordan (one of the Grey Wardens). The good news is that he has left his cell, but the bad news is that you can no longer use your disguise. Talk to Riordan and don't forget to give him the documents found in the previous room. Once he's escaped use a nearby door (M73, 6) to travel to [Denerim - Arl of Denerim's Estate - Dungeon] (M74, 1). It would be a good idea to save your progress before moving on (a lot of difficult fights ahead!).
Howe's guards will stop you once you've entered the first area of the dungeon (M74, 2) and you won't be able to prevent them from attacking your team. More fights will take place in the dungeon and each time you should focus on keeping your teammates alive, because enemy units will be using powerful weapons to stop you. Don't forget to kill archers quickly, especially since some of their special attacks will stun your allies.
During your time spent in the dungeon you'll be moving counterclockwise and you'll come across a lot of smaller rooms along the way. I would strongly recommend exploring these areas. Don't forget to provoke enemies to chase after you and to attack them far away from the rest of the guards. Aside from the soldiers and from the archers you'll also have to watch out for mabari and for Howe's mages (they have to go down first). It's also going to be important to save a couple of civilians along the way (more on that can be found in the sections describing Tortured noble and Missing in action quests).
Before you proceed to the area where arl Howe can be found (M74, 7) make sure to save your game again, because you're about to start a very difficult boss fight. Once you're inside have a little conversation with him and then proceed with the attack. Once again, I would recommend moving back to the main corridor, because you'll have more room to move and there's a chance that some of Howe's men won't exit the room with him. Don't forget to heal your team members during the battle, because Howe's attacks will result in serious injuries.
After you've defeated Howe check his body for a key and deal with the remaining enemies. You should also consider visiting nearby cells to complete one of the subquests (The lost templar) and to talk to Vaughan Kendells (M74, 9). Notice that you can ask Vaughan about a potential reward and he'll give you a key to the vault mentioned before. Once you have the key you can free him, kill him or leave him in the cell.
You must now exit the dungeon to return to [Denerim - Arl of Denerim's Estate - Interior]. I wouldn't recommend choosing the passageway located near the room where you've fought Howe (M74, 10), because you would have been attacked by a very large group of enemy units after arriving in a small room. Winning the battle would require you to issue correct orders and to constantly monitor health bars of your team members. Instead backtrack your steps to return to the passageway you've used to enter the dungeon (M74, 1).
Either way your next objective will be to return to the chamber where the queen is being held (M73, 3). Approach the door and you'll be allowed to open it. Talk to Anora and notice that the only exit from the estate is located to the south-west. SAVE YOUR GAME before heading to that location (M73, 7), because you'll soon have to decide how this quest should end.
The most obvious way to get out of this situation is to fight Sir Cauthrien and to succeed in defeating all enemy forces. I have to warn you that winning this battle is going to be EXTREMELY difficult. As soon as the battle has started retreat and order your team to remain in one of the previous rooms or corridors (you may choose the chamber where Anora was being held). The idea is to escape from the mages and from the archers which shouldn't be a big problem, because they won't pursue you. Instead wait for Howe's warriors and for Sir Cauthrien herself to show up and start attacking them. Naturally defeating Cauthrien won't be easy, because she'll be very resistant to your attacks. Keep healing your allies or even bringing them back to life using resurrection spells.
Sadly eliminating Sir Cauthrien won't resolve the problem, because in order to succeed you'll have to defeat ell enemy units, including the ones stationed near the exit. You can't provoke archers to chase you, so you'll have to organize an assault. Enter the room when you're ready and QUICKLY kill the only mage found in the room. Once he's gone retreat for the second time and heal injuries. You must now keep repeating these actions, but each time you'll want to kill only a handful of archers. Don't forget to escape once things get too tough. Once the room has been fully secured click on the door and return to [Denerim - Arl Eamon's estate] (M71, 2). You'll be allowed to resume your current main quest (The landsmeet) without having to pay a visit in [Fort Drakon].
An alternative is to surrender during your initial conversation with Sir Cauthrien. This would result in the main character being captured and transported to [Fort Drakon] (M79, 1) and you would automatically start a new quest - Captured!. You would also be allowed to choose between organizing an escape on your own or waiting for rescuers to show up.