There is a known bug involving the Purity quest. Do you have any saves before the quest? Before trying the steps below I'd first attempt to fast travel as that generally resets the followers. Vilkus may still be at Whiterun or Ysgramor's Tomb; have you looked there for him? You could also try going through the quest normally without Vilkus as if it wasn't completed; some people have claimed to be able to activate the flame without him and finish it normally. Sorry of the following doesn't make any sense, this is as specific as I can be with the details provided. This hasn't ever actually happened to me, but these are notes others have made on this issue involving bypassing the part where the glitch can occurr: [*]One way to bypass this and cure yourself of lycanthropy is to have in your inventory two witch's heads and save the game before you hand over each Companion mission. When you ask for a new job and Vilkas asks you to cure him, reload your last save, but rather than reporting the mission as complete as you did before, ask Vilkas to join you. [*]Fast travel with him to Ysgramor's tomb and go inside. Speak to Vilkas and tell him you're parting ways. [*]While still in the tomb, speak to him again and tell him you've finished the last mission. Ask him for more work and accept to cure his lycanthropy. He will then follow you to the font where you can throw in the witch's head and fight his wolf spirit. [*]The game then asks you to talk to Vilkas, but no option which can progress the mission appears, and the quest will appear in the 'completed quest' list. [*]You can, however, purify yourself once this has happened by throwing another witch's head into the font and fighting your own wolf spirit. [*]Be aware that the game still thinks Vilkas is a follower, so you will be unable to have a genuine follower once you have done this. Let us know if it gets figured out. If not, we'll try something else. You can reply to your topic in the "Reply to this Topic" field slightly above the very bottom of this page. ___________________________________ If this has helped, you may enjoy creating an account to take advantage of the other benefits, including having an easier time posting more questions and answering those by others.