It’s a flashback episode to 2008, all centered around the thrills and chills of Halloween, which is so right for the silly but spooky vibe of this show. I usually hate flashback and flashforwards, but this one was a handful of Nestles’ miniatures in my plastic jack o’lantern, and a nice mommy saying “take some more.” Because it’s there to fill in some of the missing pieces, I’m breaking my usual format of summary by girl, because this one takes place before the Big Bang that splinters the five into four quivering lumps of fear and guilt. Alison’s alive! Alive and bitchy, and alive and vulnerable. Just when you have her pegged, she seems something else again. But I can say this: it’s now pretty firmly established that Alison is not A. Because Alison is the first one to get mysterious texts from A.