Sam and Dean come to the aid of Sam's old college buddy after he is accused of a murder he swears he didn't commit. The brothers discover a shapeshifter is adopting the likenesses of others and murdering people. The brothers' race to stop the shapeshifter takes a terrifying turn when he shifts into the likeness of Dean.

The infamous "Hook Man," a vengeful spirit who kills his victims with a shiny hook that serves as his hand, terrorizes a small college town in Iowa. Sam and Dean learn that all the victims are connected to the daughter of a local minister and race to find and destroy the Hook Man's bones before he comes for them.

Sam and Dean head to Minnesota where a young boy witnesses a man vanish into thin air. Upon searching for clues, Sam is abducted by what he assumes is a supernatural being, and Dean is left to search frantically for his brother. However, both are stunned when they realize the kidnappers are human, and using the captives as human prey for a twisted hunting expedition.

To obtain a mystic gun capable of destroying the demon that killed their mother, Sam and Dean must team up with their father John and face off against vampires.

After the events at the hospital, the brothers have no idea where the demon that killed their mother is hiding. While biding their time trying to come up with an idea, they investigate murders committed by a killer clown.

Sam has a vision of Dean shooting a defenseless man, and they go to the town of River Grove, where they find the townspeople have been possessed by a virus that makes them violent.

The Winchester brothers seek the help of their family friend Bobby while investigating a series of unexplained happenings on a local college campus.

Sam and Dean allow themselves to be arrested in order to investigate a series of murders inside a penitentiary. However things get complicated when FBI agent Henricksen shows up to take over their case.