Spencer comes in and all the candles gutter and the shadows climb the walls and everybody shivers and the bodies in their boxes writhe and it's altogether a bad scene. I can't help wondering if this entire storyline were actually inspired by that one fucked-up face she made that time in the interrogation room on the day of the shovel. Remember that face? I sure do. It's burned into my memory, like I'm Emily Fields over here. And it seems to me that one single face is more than enough reason to wipe off the entire writers' room whiteboard and put in huge letters:

SEASON 3-B IS NOW SPENCER JUST GOES FUCKING NUTS OK

Spencer: "Hey fucker, guess what?"
Jason: "Spencer, so glad you could join us."
Liars: "Just noticed Spencer is bonkers. Literally this is the first we're noticing this."
Spencer: "Your sister was pregnant when she died!"
Jason: "Do go on."
Liars: "Spencer, no! You're just being weird and mean!"
Spencer: "Guess who the father was? Detective Wilden!"
Jason: "BRB I have to go threaten a policeman now."
Liars: "Spencer, that was the most fucked up thing you've done in a while."
Spencer: "Ha! That you know of."

The whole "people move on" thing comes into play, now, in a new way: Spencer's become the largest advocate for letting Ali go, forgetting about Mystery B, but it's happening just in time for her to get completely caught in the web of Mystery A. The other three have gone through a lot of good, hard work to come back around to this place where they're allowed to mourn her and say goodbye, because so much of what they went through has been about that, about putting her to rest in their hearts so they can say goodbye in the real world. And now Spencer's so tied up in other shit she can't come with them -- and out of them all, missed her the least to begin with -- so they all look just as lost to her as she does to us.