[Rest in peace Mad Jack SPOILER] So, Ruby lived out her life, with the mystery old lady watching her, stopped "Mad Jack" from wreaking havoc, and it seemed that the old lady was her all the time?
I still don't know what the old lady/Ruby said to any of the characters, but all I can guess that somehow maybe she's Ruby from some sort of alternative timeline, maybe with some connection to that throwaway bit with her turning into an alien. Seems that she should be this "one who waits", who was mentioned.
Another thing that surprised me was the whole bit about "I recognise you" with the woman on the cliff, which feels that there must be more to it. So, what with the snow appearing just moments before, maybe it will turn out that she is Ruby's mother?
Mrs. Flood was back, but nothing really got developed about her, so I can't wait for her to show up again.
A weird episode with not much of the Doctor, but I was hooked.