Supernatural’ season 9 summons its 13th episode of the year in “The Purge,” as Sam and Dean go undercover at a health spa to investigate a series of murders that end with victims mysteriously dropping hundreds of pounds.

Last week’s ‘Supernatural’ installment, “Sharp Teeth,” saw Garth (DJ Qualls) resurfacing among a reformed pack of werewolves, though his newfound happiness quickly proved less than it seemed. So, what does the 13th season 9 episode bring? What strange and unexpected challenges will the Winchesters face next?

Read on for your in-depth recap of everything you need to know about ‘Supernatural’ season 9 episode 13, “The Purge”!

An overweight man named Wayne in Minnesota wins a hot dog-eating competition against a rival who accuses him of cheating, to no avail. Later, Wayne gets in his car and reveals that he had in fact cheated, before an unseen figure grabs him from the backseat, sucking the fat out of his body and killing him. Dean learns about the case days later but still snipes at Sam about his earlier decision that they keep a strictly professional relationship.

Sam and Dean meet with Minnesota Sheriff Donna Hanscum about the crime, which continues to baffle police, as they’d established an alibi for Wayne’s competitive eating rival, Jim Morgan. The two next talk to Jim, supposing his gypsy wife Mol might have used a hex bag of witchcraft on Wayne, though the woman privately identifies the bag as a blessing in her culture, as she had been having an affair with Wayne and wouldn’t have wished him dead. Elsewhere, the fat-sucking figure claims another victim in a nearby gym.

Sam and Dean investigate the scene, learning that Sheriff Donna has gone on vacation, before Sam notices a peculiar suction burn on the victim’s back. Dean interrogates the gym owner, who reveals she’d left the victim alone in the gym the previous night, before Dean sees her to have the same suction marks on her own back. The woman identifies the mark as a treatment from Canyon Valley wellness spa, which Sam and Dean go undercover to infiltrate, Sam as a yoga instructor and Dean as a cook.

While Sam and Dean settle in, Dean gets harangued by his boss and the spa’s founder, Maritza, prepares to administer the “cupping” suction treatment on Sheriff Donna, who quickly falls asleep during the procedure. With Donna asleep, Maritza unveils a disturbing sucker from her mouth, through which she begins sucking fat from Donna. Elsewhere, Sam notices the cupping mark on all his yoga practitioners, while Dean samples some of the cafeteria’s pudding and promptly passes out.

Sam observes a groggy Sheriff Donna in treatment, before a distress call takes him to the weary Dean, still drowsy from the drugged pudding. After his recovery, Dan and Sam learn from Donna that she’d dropped 10 pounds in one session. Meanwhile, Maritza’s husband Larry pulls her aside to reveal that Sam and Dean are hunters, and their worst fears have likely come true.

Dean finds Maritza attempting to dispose of fat stores, though she insists the rash of killings weren’t her doing. Identifying herself as a Peruvian fat-sucking parasite, Maritza insists that she and Larry want only to coexist peacefully, though her brother (and Dean’s boss) Alonzo likely grew tired of portion control and fatally fed off the victims. Elsewhere, Larry confronts Alonzo about his behavior, before Alonzo finally kills his sister’s husband.

Using a special knife obtained from Maritza, Sam and Dean pursue Alonzo to the basement before the creature attacks and nearly devours Sam. Dean saves his brother at the last moment by severing Alonzo’s sucker, ending the threat. In the aftermath, Sam sympathizes with Maritza for losing her family, insisting to Dean they have no reason to kill an otherwise innocent creature.

Back at the base, Dean admits to Sam that he doesn’t feel wrong about saving Sam previously, as it had been the right thing to do. Sam counters that Dean makes himself out to be a savior, when in reality keeping Sam alive has cost far more lives than it has saved thus far. In fact, Sam posits that Dean only saves Sam for his own inability to be alone, as even his self-sacrifices prove equally hollow. Dean insists his brother would do the same if the situation were reversed, to which Sam grimly disagrees.

OUR REVIEW:

Well, given that last week's installment attempted to ease its transition back to more silly conceptual episodes, we can't say as we're entirely surprised to see 'Supernatural' in such poor form to night, baselessly lobbing Jensen Ackles and Jared Padalecki's natural charisma at a storyline vacillating between fat parodies. Sure, sending the boys undercover as a yoga instructor and cafeteria worker make for a decent sight gag, and Ackles clearly has fun with some of the broader moments, but neither the initial setup nor the ultimate execution of "The Purge" really do more than force another episode-ending conversation with Sam and Dean.

It isn't that such lighter episodes always necessarily fail or that Sam's grave insistence on Dean's inherently selfish nature doesn't ring true, but "The Purge" seems entirely disinterested in the road it takes to get there. Competitive eaters, one of whom is married to a gypsy? Sure! Crazy weight loss spa, secretly run by a fat-sucking demon? Why not! Let's toss in a few 'Fargo' nods for good measure! Who cares, right? Cheap shots perhaps, but it isn't as if 'Supernatural' seems to have much of anything to say or any jokes to make on either side of the case this week, while its characters and "surprise" villain fall predictably flat, despite the admittedly unsettling visual work behind their parasitic anatomy.

It'll be interesting to see how the brothers address Sam's brutal speech going forward, as either side makes reasonable points that adequately highlight Dean's selfish behavior in the guise of altruism. We've long passed the point of hoping that either brother could have a happy life, separately or together, but if 'Supernatural' can find something new to say on the brotherly dynamic beyond the strain placed by the current season, "The Purge" will have almost been worth it. Dean's notions of family can't provide the cure-all he wants, though Sam needs to find his own reasons to live, as well.

Well, what say you? Did you get your fill of scary ‘Supernatural’ action? What did you think about “The Purge"? Give us your take in the comments, and join us again next February 25 for an all-new recap of ‘Supernatural’ season 9 episode 13, “Captives,” on The CW! Featuring Snooki! For ... some reason!

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