Speaking With Silence

Speaking with Silence is the Thieves Guild quest which follows Scoundrel's Folly. It is offered by Mercer Frey immediately upon completion of the previous quest.

Overview

 * Prerequisite: Scoundrel's Folly
 * Quest Giver: Mercer Frey
 * Reward: N/A
 * Reputation Gain: N/A

Objectives

 * Meet Mercer Frey outside Snow Veil Sanctum
 * Enter Snow Veil Sanctum
 * Find Karliah
 * Speak to Karliah

Walkthrough

 * Have at least one piece of the thieves guild armor you were given. You will need to trade a piece with Tonilia for something better.
 * Meet Mercer outside Snow Veil Sanctum. Talk to him, and he will unlock the door. Enter it and cleave through the Draugr with him. There will be a Larceny Target on a trapped pressure plate, specifically the Model Ship which you can pick up and sell to Delvin for a leveled amount of gold (300-800). At some point you will encounter a locked puzzle door, which usually requires a claw made out of a specific material (e.g. Ivory Dragon Claw). However, this time Mercer will open it. Upon advancing after the locked door, you will be shot by a poisoned arrow and fall to the floor, you will be able to watch Mercer's and Karliah's meeting and learn more about his real intentions. After their talk Mercer will approach you and stab you, the screen will then black out. When you wake up Karliah and Mercer Frey will have a conversation, and Karliah will escape. Mercer will come over to you and stab you, and the screen blacks out again. You will wake up outside the Sanctum and you will be confronted by Karliah, whom you and Mercer are looking for. Mercer will be gone. Speak to her, and find out about Mercer Frey's treachery to the guild.
 * Note: Your followers will wait outside while you are in the dungeon with Mercer Frey.
 * You cannot pickpocket Mercer Frey until after he opens the final puzzle door, and after that you can pickpocket his Dwarven Sword of Devouring (Damage: 13, Weight: 12 ,Value: 874, Absorb 15 points of health) and his iron dagger. If you do, the dialog and animation still follow, but he threatens Karliah with his fists and cuts you with an imaginary blade.
 * After Mercer Frey unlocks the puzzle door, you can take him back to the previous pull-chain-activated gate and lock him behind. Karliah will still shoot you with the poisoned arrow. The dialog will follow but Mercer Frey will not be present.

Bugs

 * Sometimes Mercer Frey does not immediately unlock the door to Snow Veil Sanctum. This can sometimes be fixed by saving and reloading, although that is not always the case. Pushing him with sprint may also work. It is unknown whether there are any fixes for this glitch. You cannot proceed further with the Thieves Guild if this quest it not completed. (On Xbox 360 it was fixed by saving, then resetting the Xbox and loading the last save. Not confirmed if this works on PC too. On PS3 it was fixed by pushing him around a little bit using sprint when near the door). This glitch seems to be related to followers; If you have any followers near the door, Mercer will not approach it.
 * I had Sven and Barbas as companions and left the door area, took them to on side of the mound and had them "stop following" then went back to the door and Mercer Frey unlocked the door with no problems.
 * If you've hit Mercer with an attack, he may go hostile on you. Simply sneaking away until the eye closes seems to fix it.
 * I walked up to the door and sneaked  took him good 25 sec to finally walk over to me and then he opended the door.
 * I walked away from him after pushing him to the door, went into sneak (eye closed) then unsneaked. He opened the door immediately. (This worked great for me, even with a 3 other followers. Sprint-bump him next to the door and leave the mound while sneaking. As you back away he will eventually start talking about how hard it is to pick the lock on old mounds, but easy for him. Xbox 360)
 * I don't know if it affected achievements, but from what I read, you cannot beat the game without beating this quest (bug where invincible Mercer follows you everywhere, and in a later quest keeps fighting a dragon you're supposed to kill). In your console type * movetoqt TG05 * then just walk toward the locked door. Fixed it perfectly. Typed with no asteriks of course. ***Update*** I had to use this command again on another glitched quest, and it has been the only console command I've used. However I am still receiving achievements, so it didn't disable them or have any affect on my game.
 * Note on above console command: Move away from the dungeon and have Mercer follow you until you're out of sight of the dungeon, then use the "movetoqt TG05" command and it'll teleport Mercer to the door and have him unlock it. It does not seem to work if you're standing at the door and use the command while Mercer is in sight of the door.
 * This quest has a possibility for Mercer to become injured and never recover. If this occurs, the cut scene where you are shot with an arrow can take upwards to an hour to complete, if it is able to complete at all. At this time there are no known fixes to this bug, as you are unable to heal Mercer through any magical means.
 * - Actually, if you exit the room he was injured in, wait an hour and he will come to you fully healed and standing. Thus, the quest can continue.
 * - Waiting for an hour didnt work for me. Just hit him few times with your weapon, he will draw his. After that leave combat and he will be standing.
 * When you reach the cutscene with Karliah, it is possible that the cutscene will freeze. Any time this happens, just use your waiting option and wait for 3 hours.
 * Karliah may become stuck inside Snow Veil Sanctum. (PS3, PC, Unconformed for 360)
 * After running through this quest I could no longer use any station (Arcane enchanter, Alchemy stations, etc.). Reloaded to before entering the Sanctum and after completing it a second time stations worked as normal (360)
 * J'Zargos Scrolls flare on Mercer, making him aggro on you.