User blog comment:Morganaforever/Morgana's torturer in 5x08/@comment-5209013-20121117213756/@comment-5209013-20121118123030

I think you might be right and Morgana didn't know who captured her, or has deceived her. I believe Katie McGrath stated that Morgana thinks Arthur has been the one who ordered for Morgana to be imprisoned (a theory that is assessed by Morgana's surprise when she learns that Gwen didn't know about it). Anyway, I'm almost convinced that her capturer should be a powerful sorcerer, as he managed to keep a powerful sorceress and a dragon locked up.