Many critics didn't like this episode because it revisited a once-opened sub-plot. I agree that it's a bit too late to get back to a sub-plot while the show becomes nearer to its end. But I found that this sub-plot has something to do with the main plot. Actually, it's merged very well with the story, and it seems that it even adds to the story. So what's the wrong with that?! Also, it's darn entertaining!
I loved how creepy the atmosphere of Past Perfect is. Nevertheless, it assures that Castle Rock suffers a great deal of inconsistency in tone, and style.
What really got my attention is how much this show is related to The Shining. In fact, it doesn't only take place in the same universe of The Shining, It expands on this universe using The Shining's rules. Maybe in a messy way, but it still a decent one.
(8/10)