User blog comment:Jimeee/Dragonborn officially released on Xbox Live/@comment-99.44.140.176-20121204155236/@comment-213.205.234.16-20121205115210

You need to complete the main quest mission where you are sent by the greybeards to retrieve the horn, but delphine got to it first. As soon as i completed that 2 Cultists attacked me, you'll know them when you see them!