User blog comment:Ktrfgfg/Chapter 53 and chapter 54 predictions/@comment-10733658-20140107155701

Theory concerning the woman seen in Eren's vision:

I believe she is a previous Coordinate. We already have evidence that Eren possesses knowledge he should not, such as the exact means to active the transformation. Grisha also mysteriously told him that he would have to rely upon "their memories". The flash he sees seems to suggest he is seeing through the eyes of that mysterious woman, experiencing a moment in her memories.