Taking Care of Business
How To Unlock: Join the Thieves Guild
In order to kick off the Thieves Guild questline, you’ll have to do a small quest for Brynjolf in Riften, on the square. He’ll be there at his stall between 8am and 8pm. Once you’ve done that he’ll want to meet you at the Ragged Flagon under Riften in the Ratway, which is the start of the Taking Care of Business quest, which is your way into the thieves guild.