Board Thread:General Discussion/@comment-11464223-20151109020125/@comment-26116863-20151109174236

Nimue being the dark one really makes Merlin telling them that she is the only one that can help them, and to go find her, really weird.

The only way that would make sense is if he meant the woman Nimue DO used to be. Which might mean more time travel. Or, they could try to see if the original Nimue is even still in there somewhere, or if it's just her evil essence.