Loved it. The setting in stone is probably my favourite example of time travel rules done wonderfully, and the most sinister bit in the entire episode. The concept felt as realistic as hell, yet truly frightening, which made it all the better. And it's the way I always imagined time travel dynamics, although I guess one might call it too simplistic.
Oh, and it's my favourite appearance of the Statue of Liberty since Cloverfield.
Excellent sound work as well.