The Collector Is Draining Resources From Riverspring. Pay Him A Visit In His Manse In King’s Landing To Put Things Right.
Objective Point A
After you receive this side quest from collecting the secret documents from the tunnels under Riverspring (see “Chapter 8, Part 2” in the walkthrough), head off to King’s Landing. You can do this quest anytime you’re roaming King’s Landing from Chapter 8 through Chapter 13.
Objective Point B
Look for the door to the Collector’s manse in the noble section of King’s Landing. It’s at the end of the long balcony near the central staircase.
Your Enemy Is Hiding Around Here Somewhere. Find Him And Avenge Your People.
Objective Point A
A greeter welcomes you inside the manse. He refuses to admit that Mallador Brax is the Collector, and when you force the issue, he calls the guards on you.
You have to fight a handful of guards in the small room. You can use the central table to your advantage by keeping melee enemies at bay, and if you have a ranged weapon, you can attack them without them reaching you. However, one of the enemies wields a crossbow, so you’ll have to deal with him with projectiles of your own or cut him down when you reach that side of the table.
Objective Point B
If you open the door next to the first room, a burly cook with a meat cleaver will charge at you. He has a lot of health but no armor. Stun him a couple of times and slay him with a steady supply of damage. You’ll return to the kitchen later, after you’ve recovered the Key to the Collector’s Cellars.
Objective Point C
Take the stairs to the top floor and battle a series of guards in the various rooms. Open each door and fight that group one at a time; you don’t want to run around and alert any other guards to your position. Use the doorways as choke points to keep the enemies from charging out and surrounding you. Attacks that damage multiple foes or that spread, such as fire and poison, are very effective in the small rooms.
Objective Point D
When you finally track down the greeter who first met you at the manse, kill him and his buddies and then loot the Key to the Collector’s Cellars from the man’s corpse. Return back downstairs.
Objective Point E
Use your new key on the grate locking the basement area. Enter the cellar and prepare for lots of resistance.
Objective Point F
It appears to be a normal, relatively empty cellar. However, if you use the Vision of R’hllor on the western wall, it reveals a secret mechanism. Pull the candle holder and the wall slides up to expose a new corridor.
Objective Point G
In the secret corridor area, you’ll run into more of the Collector’s guards. Dispatch them in similar style to how you handled the earlier enemies. Take each group slowly, one at a time, and don’t move forward until you know you’ve cleared all the enemies in the immediate area.
Objective Point H
You discover that the Collector is a slave trader and a thief. He has close to a dozen prisoners awaiting export to the slave trades. To free them, you must find the Key to the Collector’s Slave Cells from the guard up ahead.
Objective Point I
Search for another secret passage at the wall marked with a black skull plate. Use the Vision of R’hllor to reveal the door and continue on.
Objective Point J
Sneak up on the next set of guards. Try to kill one of them before they can counterattack, and stun the second one quickly thereafter. As long as you don’t let all of them attack you at once, you should be fine.
Objective Point K
Hunt down the guards to the east. You can retreat back down the corridor toward the slave cells if you have a ranged weapon and want to keep space between you and your targets. Slay the guards as they converge, and remove the Key to the Collector’s Slave Cells from the purple-robed enemy. Return and free all the prisoners from the slave cells.
Objective Point L
More guards fill the rooms to the east of the slave cell area. If you confront them, hit them with a damaging attack inside the room. Next, use the doorway as a choke point to hold them back as you continue wounding them until they fall one by one.
Objective Point M
You’ve finally caught up with the infamous Collector. He taunts you as you enter his office, and then the three enemies converge on you.
Make sure you’ve switched to a blunt weapon: two of the enemies, including the Collector, wear heavy armor and the third wears light. Stun immediately and take down the enemy in light armor as quickly as you can. Drink a healing potion if your health drops below half; the Collector can deal a huge amount of damage in one shot with his two-handed mace, so you don’t want to drop too low on health and put yourself at risk of dying with a single enemy blow. Stack damage on the other guard until he’s out of the fight, then throw everything else you have at the Collector until he’s down. After a hard-fought struggle through the manse, you have your vengeance and some nice rewards to line your backpack, including the Stranger statuette from the Collector’s loot stash.