Part 4/7:
As the brothers delve deeper, a second murder takes place at a local gym. The victim, like Wayne, is found with strange suction marks on her body. These marks become a key detail that builds the case around a supernatural entity at play. Sam and Dean work diligently to connect the dots between the victims and the gym's suspicious activities.
They soon realize their investigation leads to a dubious weight loss spa, Canyon Valley, where the owners, Larry and Maritza, claim to provide weight loss services that seem too good to be true. They infiltrate the spa under the ruse of personal trainers, where they discover the truth about the spa's practices: the owners use a form of beastly siphoning to remove patrons' excess fat via a supernatural technique.