Sam, a soon-to-be college graduate, has an interview set up to attend one of the most prestigious law schools in the country. His brother Dean, whom he has not seen in several years, unexpectedly shows up in the middle of the night to tell him that their father went missing while on a hunting trip. Leaving his girlfriend behind to find their dad, Sam joins Dean in order to find their father in Jericho, a small town where unmarried men have disappeared without a trace.

Sam and Dean head to Colorado to find the coordinates that their father left in his journal. There, they pose as park rangers to investigate the disappearance of campers. They soon discover that they're up against a Wendigo, a mythical creature from Native American folklore.

Dean comes across an article in the newspaper about a mysterious drowning. Sam and Dean soon find that several people have drowned in the same lake, but bodies were never found, leading the brothers to believe that a spirit is haunting the lake.

Sam and Dean meet a flight attendant who was aboard a plane that crashed with mysterious circumstances. They soon figure out her connection to the crash, but not until they are on board a flight with the woman.

Sam and Dean hear about a man who died of a stroke while in front of a mirror. After visiting the family and interviewing the members, the brothers are led to believe that Bloody Mary may have caused the man's death.

One of Sam's friends, Zach, is accused of murder, and Sam offers to help him by checking up on his younger sister, Rebecca. While visiting her, Rebecca convinces the brothers that Zach didn't commit the murder because he was with him when the murder happened. But could Zach be in two places at the same time?

The brothers come across a girl whose boyfriend fell victim of the Hook Man. It's up to Sam and Dean to destroy the ghost's bones before she and her father become victims as well.

A construction worker is killed when insects burrow themselves into his brain. Sam and Dean research the history of the town and find that a new housing development is being constructed on a sacred tract of Indian land. The land was put under a curse when the reservation had been destroyed. Now, it's up to the brothers to reverse the curse and kill the swarms of bees, locusts, spiders and beetles.

In the ninth episode of season 1(s1e9) of TV show “SUPERNATURAL”, the brothers make a decision to head home in Kansas after Sam has some nightmares. They discover that what he saw in his dreams is actually coming true. Finally they have fight with a poltergeist only to be saved by the spirit of their mother.

Sam and Dean travel to an abandoned sanitarium where they find that the patients once revolted against cruel and unusual punishments given to them by the head doctor. The brothers search the area for lost college students, but the spirits make them go insane, and end up turning Sam against Dean.

Dean travels to a town that's hiding a dark secret about a scarecrow. Meanwhile, Sam decides to separate from Dean and try to find their father, who Sam believes is in California.

During a fight with a demon, Dean is electrocuted, causing serious, and potentially deadly, damage to his heart. Sam tries to find a way to save Dean, and comes across a preacher who claims he can cure the incurable. But the brothers soon discover that the preacher's miracles are happening due to help from the Grim Reaper, who trades one life for another, less worthy life.

Dean and Sam travel to Missouri after Cassie, one of Dean's ex-girlfriends, calls him to investigate mysterious, racially motivated murders. They find that each murder involves a semi truck that has no driver and leaves no tracks. Meanwhile, Dean has to deal with the feelings that he still has for Cassie.

Sam has a premonition about a man's death that is staged to look like a suicide. Once Sam convinces Dean to investigate the case, they are puzzled when they can't find proof that something supernatural was behind the death. However, they soon come across a recluse, Max, who uses telekinesis to kill off family memebers he didn't get along with.

After hearing the story of a boy who claims to have seen people disappear before him, in the fifteenth episode of season 1(s1e15) of TV show “SUPERNATURAL”, Sam also mysteriously get lost. Dean then in the garb of a policeman along with Kathleen, a real cop searches Sam to find out that he has been captured by a local family.

In the sixteenth episode of season 1(s1e16) of TV show “SUPERNATURAL”, Dean and Sam go to Chicago to investigate a murder case. There they find out that Meg is responsible but Meg clarifies that it all is actually a trap set out for their father. The brothers fight with the spirits unleashed by Meg.

Dean and Sam have to face the ghost of Mordecai who has been living in an old Texas farmhouse. The brothers discover that Mordecai is not a normal spirit, but rather a tulpa, who was created by thousands of people believing in him after the fake legend of him was posted on a popular website. Now, Sam and Dean must stop his spirit from killing any more people who enter the house.

Sam and Dean set out for Wisconsin in the eighteenth episode of season 1(s1e18) of TV show “SUPERNATURAL”. There small kids are falling into coma for no reason apparent. It comes out to be the misdoings of a witch. This witch extracts ‘life-force’ from the children. The brothers fight with the witch.

In the nineteenth episode of season 1(s1e19) of TV show “SUPERNATURAL”, Sam and Dean proceed to investigate next case in which a couple is murdered. The murder is investigated and it is found out that a painting is responsible for the couple’s death and everyone who had owned that painting had died.

When a vampire hunter and friend of their father's is killed, Sam and Dean are shocked when their father arrives to help them solve the crime. John finds that vampires have stolen a gun that has the capability of killing all evil beings. The brothers, along with their father, set out to get the gun back.

After Sam has a vision of family being attacked by a demon, similar to the way his mother was attacked, he and Dean, along with their father, travel to Salvation, Iowa seeking revenge on the demon now that they have the colt gun. However, things don't go as planned when Meg calls the boys and their father to let them know if they don't return the gun, she is going to kill their friends. The Winchesters devise a plan in order to trick Meg and kill the demon.

Sam and Dean, in order to save their father from Meg, enlist the help of a family friend, Bobby. When Meg shows up at Bobby's, the brothers are able to exorcise the demon from her body and get her to tell them where their father is being held. Sam and Dean race off to rescue their father, resulting in a final showdown between the Winchesters and the demon they have spent their lives looking for.