The Secret of the El'durath was a Quest released on 7th December, 2013. In this quest you are designated as an assistant researched for the famed Reginald M. Sercath, however you wake one morning to find him missing. A letter on the doorstep written by him is the only clue you have.
Winter Event 2013 Badge
This badge was given to users who started the Winter 2013 quest.