A Cornered Rat

A Cornered Rat is a quest in The Elder Scrolls V: Skyrim. It is part of the Main Quest.

Overview

 * Prerequisite: Diplomatic Immunity
 * Quest Giver: Delphine
 * Reward: N/A
 * Reputation Gain: N/A

Delphine
During Diplomatic Immunity, you will find a note talking about Esbern, an old friend of Delphine. Delphine will tell you to go to the Riften Ratway to find him before the Thalmor do.

Brynjolf
Before you can talk to Esbern, you need to find him. Delphine points you in the direction of an old friend named Brynjolf, who can be found in the market place of Riften. When you talk to him, he will ask you to perform the simple task of stealing a ring from a box on another booth while he distracts everyone. Whether or not you succeed, he will tell you to meet him in the Ratway under the city. It is even possible to ignore him completely and go straight down into the Ratway.

Note: Members of the Thieves Guild can talk to Brynjolf inside the The Ragged Flagon - Cistern to advance to the next part of this quest.

Ratway
Note: Before you enter the Ratway, it is possible to be attacked by Thalmor (2 Warriors and a Wizard) outside the entrance to The Ragged Flagon - Cistern. Inside, after the attack, a spy named Gissur will be identified by Guildmembers and killed. From his body the Dragonborn can loot Gissur's Note.

Once you are inside the Ratway, fight your way through a few enemies to the headquarters of the Thieves Guild. When you are there, speak to the bartender about Esbern. He will not talk unless you have a high persuasion, 140 gold coins, or beat him in a fight. Then he will give you Esberns location in the Ratway Warren with a warning that the Thalmor are looking for him as well.

Note : If you are a member of the Thieves Guild, you may simply enter through the secret entrance in Riften graveyard as you normally would. The bartender will tell you what you need to know without any problems or other requirements.

To get to the Ratway Warrens, you must go through the Ratway tunnels. Simply turn right and then go down the hall and turn left. You may have to fight several Thalmor before dropping down into a hole in the ground. When you have descended, turn left and go down until you find the door to the Ratway Warrens.

Immediately entering the Warrens, you will see a large door near the left corner of the room. Go over to it and attempt to open it to engage Esbern in conversation. Tell him that you are the Dragonborn and he will let you in. After conversation, you must lead him out of the Ratway and back to Riverwood. After leaving his room, you will be attacked by a Thalmor mage and soldier, dispatch them and follow the marker back to the Ratway Tunnels and out to Riverwood.

Bugs
NOTE: On PC you can disable the door, the re-enable it through the console command by clicking the door with command open, then entering disable, then enable. Or just leave the door disabled. Tips
 * In first conversation, Esbern is voiceless and after the conversation he fails to open the door. This can be sometimes fixed by deleting (BACKUP FIRST!) "Skyrim.ini" and "SkyrimPrefs.ini" from "C:\Users\[USERNAME]\Documents\My Games\Skyrim". All preferences are now default. If everything works it is recommended to set up preferences again rather than overwrite new files with backup.
 * Esbern will fail to come out of his room. This can sometimes be remedied by spamming the "E" key, or you may use the dev console "TCL" command to disable collision.
 * If this doesn't work try using the TCL command to walk trough the door. Shut down the TCL, talk to him, when he starts using the chest kill him. Then you can talk to him again and tell him to lead the way.
 * You might just be unlucky and not even be able to talk to him even if you follow the previous steps
 * After you talk to him, type setstage MQ202 160 and setstage MQ202 170, it'll open the door and make him talkative again
 * Sometimes this quest will fail to start at all and never even show up in your quest log after completing Diplomatic Immunity, in which case you will have to skip ahead to the next quest, Alduin's Wall. In the dev console, type setstage mq203 5.
 * If he ever gets stuck again just kill him.
 * If killing doesn't work try failing to pickpocket/place an item.
 * When you get outside he is just as a regular companion.
 * If he gets stuck just start a dialouge with him, keep doing it if it continues.
 * Make sure you kill everything on the way outside beforehand, Esbern instantly summons a Frost Atronach in combat which will get him stuck occaisionally.

Follow this link and do as the OP says http://www.minecraftforum.net/topic/786124-skyrim-a-cornered-rat-bug-fix/

Tlc didnt work .. he just closes the window anyhow

"FO3 Archive Utility" seems to work best. Download that from

http://www.fallout3nexus.com/downloads/file.php?id=34 {C file>open>find your skyrim data folder, pick voicesextra.bsa, extract all to your desktop, move it back to your data folder. You could also try the console command "setstage mq203 1" to skip the quest, but this does not solve the voicee issues.