"Supernatural" fans are teased with another promo video released for the next Season 9 episode. The promo video in the Hypable report shows Sam (Jared Padalecki) and Dean Winchester (Jensen Ackles) investigating an interesting case in Episode 13 titled "The Purge" where someone or something kills people at a weight loss spa by sucking out all of their fat.

In the promo video, the Winchester brothers pose as FBI Agents asking questions about what happened to the victim named Wayne. The female officer declares the case made them stumped and described that the victim suffered massive organ damage.

"Ruptured spleen, pierced liver, collapsed lung... Looked like everything was sucked right out of them," the officer told Sam and Dean. The promo video's funny part comes when the officer some donuts and Dean did not hesitate to get a piece.

Credit: YouTube/The CW Television Network

The official synopsis for the next "Supernatural" Season 9 episode has revealed that the hunters will be going undercover to dig deep and find out the culprit in the killings. Since the victims ended up weighing hundreds of pounds lighter, Sam and Dean suspected witches are responsible for the victim's extreme weight loss.

Sam gets hired as the fitness instructor in the Canyon Valley Wellness Spa while Dean, who really loves food and eating, takes on the kitchen duty. Still images from the upcoming episode show Sam noticing weird marks on the customer's body. Click HERE to see photos.

The synopsis for Episode 13 "The Purge" reads: "SAM AND DEAN GO UNDERCOVER AT A SPA - Sam (Jared Padalecki) and Dean (Jensen Ackles) investigate recent murders where the victims were hundreds of pounds lighter after their deaths. Suspecting witches, the two go undercover at a fancy day spa that all of the victims had attended for weight loss. While Sam is hired as a fitness instructor, Dean takes kitchen duty. After Dean swipes some tainted food and passes out, the guys realize someone is drugging the guests and literally sucking all of the fat out of them until they die."

Watch "Supernatural" Season 9, Episode 13 "The Purge" to find out if Sam and Dean were able to solve this case. The brand new episode is scheduled to air on Tuesday night, February 4, at 9 p.m. ET on the CW network.

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