I'm currently working on the quest "Alduin's Wall". I got to the entrance of the Sky Haven Temple but Esbern is gone. Since he is not there I can't do the blood sacrifice and move forward with the quest. I have tried waiting multiple day's to see if he would show up. I have also tried fast traveling to a different place and back. None of them seem to work, and since this is a main quest line that I can't complete, I don't know how I am going to keep playing unless I completely restart the game (which if I have to do I will simply be done playing the game all together). Any help/solutions?