On Supernatural Season 13 Episode 11, Donna calls upon the guys for help when her niece, Wendy, goes missing. Sam isn't completely on board with taking on the case because it's not something the guys generally deal with. Dean reminds Sam how Donna is family to them, and they need to help her if they can. 

Sam eventually relents, and agrees to help out. Sam, Donna and a man from the FBI named Clay go to the police station to interview a possible suspect. Unfortunately, the suspect isn't able to offer any help, but Dean is able to find a lead thanks to a woman who saw Wendy as a diner called Conner's. Dean quickly realizes there is a pattern of people going missing from the diner. 

Sam and Donna soon meet Dean at the diner where they find out the manager of Conner's is giving people over to a man who is selling their body parts on the dark web to monsters. The guys are able to track down the warehouse where the feed is coming from, and they call Clay to help. 

They soon find out Clay is no actually in the FBI, but he's the one who is behind the bidding website. He is able to take Sam hostage, and starts a bidding war on Sam's heart. Thankfully, Dean is able to shoot Clay before Clay is able to kill Sam, and they're are able to save Wendy. 

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