I was maybe a little optimistic last week when I suggested that Supernatural's writers would be shelving Sam's Lucifer problem. After Sam and Dean make a break from the Leviathan-infested Sioux Falls hospital (with a little help from Bobby), Sam resumes getting trapped in his own head again and he--and we--aren't so sure he's doing as well as he says he is. Thankfully, the whole episode doesn't get swallowed up by this plotline, as Sam learns about a series of killings similar to a hunt he, Dean, and their dad went on for a brain-eating monster 13 years ago. Sam, feeling responsible for the monster on the loose, sneaks off to investigate and take it down.
The big question for this episode is whether or not people (and supernaturals) can change their nature. While for the purposes of "The Girl Next Door" it has more to do with the "monster" from Sam and Dean's past, it's pretty obvious given how the beginning of this season has gone down that it's as much about the Winchester boys. Sam, in particular, can't stop keeping secrets (even if they're secrets that could get everyone killed) while Dean keeps on seeing the world in black and white and making decisions that get the boys in deeper and deeper over their heads.
Jensen Ackles' direction is fine--it doesn't get in the way of the actual story or anything and just kind of lets it tell itself. The flashback scenes with Sam were a little clunky somehow, maybe because the whole "we're both freaks" thread and surface similarities between Sam and Amy were so on the nose. In the present, the reason why the monster is active again is pretty easy to figure out from the start, and I do wish the story had spent less time trying to keep such a transparent twist a secret. Also, does it really make sense for flashbacks to be sepia toned if they're taking place in the late 90's? I don't even want to think about the audience that thinks that 1998 was ancient history.
Supernatural airs Friday nights at 9 on the CW.