Sam and Dean follow the coordinates left in their father's journal and land in the middle of the woods where they investigate the disappearance of several campers. The two brothers soon learn they are dealing with a Wendigo, a creature made famous in Native America legends. A Wendigo is a former human whose cannibalism has transformed him into a creature with superhuman strength and speed that feasts on human flesh.

Sam and Dean investigate a series of mysterious drownings written off as suicides. They discover the spirit is an angry little boy with the power to travel through water who is taking revenge on certain town inhabitants for a dark secret buried long ago. Dean forms a bond with a young boy who seems to have the power of premonition.

On TransNational flight 2485, a man possessed by the spirit of the Phantom Traveler causes the plane to crash, leaving only five survivors left alive. Sam and Dean must exorcise the angry spirit before it attacks the survivors. The brothers realize the only way to do that is to take the battle to the skies.

In suburban Nebraska, a group of partying high school teens jokingly dare their friend Charlie to look into the mirror and repeat "Bloody Mary, Bloody Mary, Bloody Mary," not knowing this will unleash a series of mysterious murders. Sam and Dean realize that Bloody Mary has the power to travel through all reflective surfaces when she is hunting a victim. Worried that teens are accidentally summoning Bloody Mary, Sam and Dean race to destroy the violent spirit before she can kill again.

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.

After a construction worker is killed by insects burrowing into his brain, Sam and Dean investigate the town's history and find that the new housing development is being built on sacred Indian land. The Indians put a curse on the land after their reservation had been ravished and destroyed. Sam and Dean must find a way to survive and kill the deadly swarm of bees, locusts, spiders and beetles.

Sam is haunted by a vision of a woman trapped in his childhood house and convinces a reluctant Dean that they need to go home. Upon arrival, they meet the woman in Sam's premonition and she reveals that the house is haunted. Looking into their personal history, the brothers discover their father had visited a psychic after their mother's death and they turn to the same woman for answers of their own. Together they discover a malevolent poltergeist has inhabited the house and set out to exorcise it, but are blindsided when another unseen spirit steps in.

Sam and Dean investigate an abandoned sanitarium and discover that when the hospital was open, the patients held a revolt against the cruel and unusual punishments inflicted by the head doctor. While the brothers search the premises for four lost college students, the tortured spirits cause them to go insane, turning Dean against Sam.