Welcome to “The Lizzie Borden Bed and Breakfast Museum.”  You can check out any time you like, but you can never leave.

While things seem quiet on The Darkness front, Sam and Dean investigate a double murder at a B & B which used to be the home of the notorious accused axe murderer, Lizzie Borden.  But is the culprit a serial killer or ghost or something else?  What’s nice about this episode is that, once again, on the surface this seems like a filler episode — a monster-of-the-week story to tide things over until the brothers get back to tackling the mystery of how to fight The Darkness/Amara.  Instead we find that Amara is closer to the Winchesters than they think (or, at least, closer to Dean) and growing stronger everyday.

**********CAUTION********** SPOILERS DEAD AHEAD **********CAUTION**********

What starts out as a simple investigation into the ghostly axe murders of a couple at the former home of Lizzie Borden turns into the next big chapter in the story of the ever-growing “Darkness” – and the ever-growing Amara (Yasmeene Lily-Elle Ball). Because Amara’s favorite meal is human souls, the Winchesters get to revisit the notion of what effect a missing soul has on a person. From past experience with soulless Sam, they know that that a soulless being is very efficient, never sleeps, thinks clearly (albeit rather coldly) and has no problem with killing. They are also learning that it can make some people go dark side very quickly.

This week, with the quirky Lizzie Borden afficionado, Len (Jared Gertner), they learn that Amara’s soul sucking does not always cause an immediate murder spree. Len is more like soulless Sam quirky-lite. He’s introspective to the point of making other people (okay, mainly just Dean) want to kill him instead of the other way around. Len reminds me so much of Buffy the Vampire Slayer’s nerdy Jonathan Levinson (Danny Strong). He’s sympathetic even as he feels himself on the road to becoming evil. I wouldn’t mind seeing this character again on the show.

Sydney, the killer babysitter (Tess Atkins), on the other hand, takes the soul sucking fallout in another direction. Not only do we find out that the mere touch of Amara can feel like “ecstasy-orgasm chocolate cake” (which sounds pretty good to me) but the removal of a soul is freeing and can make a person literally worship The Darkness. It makes you wonder if Amara is only satiating her appetite or actually building her own army of followers. It would explain the sudden need for the monstrous things that go bump in the night, like last episode’s “nachzehrer,” to start building their own armies. If that is the case, if somebody has to get all of the bad guys and good guys together to fight The Darkness, of course it would have to be the Winchesters.

Finally in this week’s episode, in addition to deeper exploration of past Winchester experiences like soullessness, I love the way the writers are dropping in canon references like having the first doomed couple mention The Ghostfacers.   Keep up the good work #SPNWriters!

Take an insider look behind the scenes of “Thin Lizzie” with executive producer, Jeremy Carver.

https://youtu.be/ftjXsohU4J8?list=PL6A7D019D023E7717

Supernatural airs on The CW on Wednesdays at 9/8c.  Full episodes are also available at the CWTV.com and On Demand (check your cable listings) as well as on iTunes, Amazon, Hulu and Google Play.