User blog comment:Morganaforever/Morgana held captive in series five/@comment-4062486-20120727052226/@comment-4650675-20120727084937

Yeah, that's why I don't think that the one holding her captive is Mordred either. Maybe both Morgana and Mordred were being held captive by the same man. This would explain his disappearance for so long, and also how they reunited.