Let's just address something real quick that has nothing to do with anything else, before we get back to Supernatural's enduring obsession with moms. Rowena (Ruth Connell) said that Lucifer (rocking a shiny new meatsuit in the form of Rick Springfield) can't be tossed back into the cage while in a vessel... Except that's literally how the Winchesters got him locked back up the first time around, back when seasons 5's "Swan Song" was the definitive episode of the series. It was all so simple back then!

No, but really, Supernatural, don't start mucking up mythology already. The slow-burn introduction to season 12 that "Keep Calm and Carry On" and now "Mamma Mia" have given us are a welcome change from the usual out-with-the-old approach to season premieres... To the extent that, by the middle of "Mamma Mia," I just needed the (literal) torture to be over. Who knew that one day, we would have a show on our hands where handsome leads tied to chairs with minimal material covering those sweaty, heaving muscles would be kind of old hat? Been there. Done that.

The same can't be said for Supernatural's newest edition of "Winchester Mommy Issues," though. Pining for Mary ( Samantha Smith) and looking wistfully at old photographs while getting wasted in some lonely corner of wherever they're squatting this week is pretty standard Winchester operating procedure — particularly on the Dean Winchester ( Jensen Ackles) model. Two episodes into the post-Darkness world, and Mary Winchester is still kicking, struggling to make sense of the two co-dependent, thirty-something, monster-slaying-and-occasionally-possessed-by-the-devil-himself brothers who were barely out of diapers (or, in Sam's case, still firmly in diapers) the last time she saw them.

This woman was plucked from an afterlife she doesn't remember, following a horrific death she feels responsible for, into a life with two strangers claiming to be her children — in a world she barely recognizes. Mary griping that Dean wouldn't let her drive the Impala this week? LADY, YOU DON'T HAVE A VALID DRIVER'S LICENSE ANYMORE. Granted, Dean probably doesn't either, but that's not the point. He has a wallet full of quality fakes, okay?

"Mamma Mia's" greatest strength was in exploring the newest wing of Winchester Family Angst, and did a good job of tackling the issues from both Mary's and her son's sides. Mary Winchester obviously wants to fill that mom-shaped hole in Sam ( Jared Padalecki) and Dean's lives, and the Winchester brothers obviously want her to as well; but that's something easier said (and fantasized about) than actually done.

Sam and Dean have built lives around that empty space... And in some ways, even managed to fill that space with surrogates, with each other, and with an idea of who and what Mary Winchester was. Over time, that shape changed and shrank and scabbed over so it didn't hurt quite so much, didn't demand constant attention. It was a small thing played for laughs at the end of this episode, but Dean's astonishment that Mary's famous meatloaf was store-bought and that she "doesn't cook," was sure to be the first of many blows to the idea of Mary Winchester that her sons created over the years.

This is going to be something that Dean struggles with more than Sam. Mary and Dean's relationship has defined Dean from the first episode of the first season of Supernatural. Four years old when she died, Dean has memories to work with and over the course of the series, we've learned that he's guarded those memories closely.

Remember when Dean and Sam went to Heaven in season 5, and it sucked because their respective memory-fueled Heavens seemed to exclude each other from their supposedly shared eternities? Sam had filled the gaps in his family with friends, dogs, and school. Dean clung to his memories of Mary, and it became apparent that these were not memories that anyone bothered to share with Sam as they grew up. Dean has a solid idea of his mother — colored by a child's perspective and fueled, no doubt, by his father's own idealization of the dearly departed — but Sam, on the other hand, has a relatively blank concept of his mother. He never had the famous meatloaf. He doesn't have to work to fit the truth about it into his own notion of reality. The Mary Winchester in his mind isn't as readily defined as Dean's is.

That Supernatural left us with a final scene of Sam bonding with his mother over their shared "otherness" while Dean drank alone with his memories and his pictures, was telling. The crisis with the British Men of Letters may be over for now and Lucifer may be looming like an inevitable herpes flare-up, but the biggest monster threatening the Winchesters right now is their own flawed humanity.

Supernatural airs Thursdays at 9/8c on The CW.

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