hi there

i have put allot of time into my character and as i am going through the main quest line. the quest line just stops. After completing Diplomatic Immunity i am supposed to receive the quest (A Cornered Rat) straight after but all i get is the lady telling me to go speak to this guy. When i go and speak to him all i get is the thieves guild quest line. in my quest screen the A Cornered Rat inst there and i have checked videos and you are supposed to receive the quest straight after completing Diplomatic Immunity.

please help thanks