Board Thread:General Discussion/@comment-25926288-20151026005934/@comment-24218843-20151026025836

8Rob wrote: Avatar Beta wrote: Actually, I think Nimue is the first DO and the one in flashback. Merlin probably meant that becoming the DO destroyed her in a sense that she was no longer who she once was. Totally

I just rewatched the scene and now I'm 99% she was that Dark One

They just got a guy to play the role today to keep the secret until 5x08: Nimue i was like "who's Nimue?" and then i looked it up and saw she's Lady of the Lake/Viviane. I totally think that Viviane is either the first Dark One and/or the one who trapped Merlin in the tree in this episode.