Sam and Dean investigate a case in Chicago, where they discover that various mafia-esque monster families are, unknown to humans, running the underbelly of Chicago. One is a family of shapeshifters run by Margo Lassiter, whose leadership is thrown into question when her brother David returns home. The other reigning family in town is made up of werewolves, lead by Julian Duval. While in Chicago, Sam and Dean meet Ennis, a man with a personal vendetta against the monsters. The Winchesters warn Ennis about heading into the hunter lifestyle, but Ennis refuses to listen and starts down a dangerous path.
Season 9 Episode 20 of Supernatural was watched by 2,030,000 viewers, resulting in a 1.00 rating in the 18-49 demographic.
Sam Winchester is a college student bound for law school, determined to escape his family's past - unlike his older brother, Dean. Ever since they were little their father has been consumed with an obsession to find the evil forces that murdered his beloved wife, and recruited his two young sons to help them. They have grown up as hunters of the supernatural. Sam escaped this way of life after high school, and now has a happy life with his girlfriend, Jessica, and a promising future career. Dean, however, stayed behind with his father to join him in his "hunting".
After Dean arrives for Sam's help when their father goes missing, Sam must join his brother to find him. His one weekend trip to search for the missing John Winchester becomes an ongoing quest after a horrible tragedy ruins any thought of a happy life for Sam.
The two brothers, bound by tragedy and blood to their mission, travel across the country encountering terrifying and dangerous forces most believe to be nothing but superstition and folklore, such as the Lady in White, the Indian beast known as the Wendigo, Phantom Travelers who cause plane crashes, Bloody Mary, and many more.