Redshift Community

This is probably me just being careless but I beat this game a year ago and now can't get the actual Thieves Guild quest. I did the Lord Drengi quest and also have made my way into the Governor's castle but am unable to locate the amulet. Help me out please.

If you go to the first floor there is a woman, she'll talk to you. Kill her, and she throw the amulet.