So I broke the quest line by taking Mercers Plans before I even started the thieves guild. Anyways, after I completed the quest "hard answers" Karliah gave me the nightingale blade and just left and the next quest wouldn't start. I did the fix where you have to go back to snow veil sanctum and get poisoned again by Karliah. I then woke up outside with Karliah just like in "speaking with silence". But all it did was "Started: Speaking With Silence" then a few seconds later "Conpleted: Spewking With Silence". Then Karliah walked back to the Sanctum. Is there other ways to fix this or am I doing this wrong? I also put mercers plans back in the riftweld manor.

http://www.uesp.net/wiki/Skyrim:The_Pursuit#Bugs might help.