A mysterious death draws Sam and Dean to a town full of old-school magicians. Their investigation leads them to Charlie, Jay and Vernon, three friends who were famous magicians in their day but have now been replaced by flashier, younger magicians. One of them has made a deal to acquire real magical powers, but the price was extremely high. Sam and Dean must figure out a way to reverse the spell before others are harmed.

Sam and Dean enter a small town in Iowa, where three men have inexplicably beaten their wives to death. The guys realize that behind the murders is a Siren, a creature that can take different forms and desperately needs love and compels people to destroy themselves as a show of devotion. The Siren eventually puts Sam and Dean under their spell and pits the two brothers against each other in a fight to the death.