"Something Wicked This Way Comes" is also the title of a Ray Bradbury novel in which two teenage boys encounter Mr. Dark, the owner of a mysterious carnival, who has offered secret desires to several people, only to bind them in service to the carnival.

An old man, Daniel Elkins, sits scribbling in his journal, in a bar in Manning, Colorado. After leaving the bar in a hurry, Elkins is confronted by the woman, Kate, leading the group he saw earlier in the bar. Elkins attempts to load an old 5 shot Colt however after a struggle, he is murdered.

When Sam and Dean read about Elkins death, Dean recognizes the name from John's Journal. Arriving at Elkins' cabin, the boys find it ransacked and in chaos. Amongst the wreckage Dean finds a journal, a lot like their father's, and also a message. A mail drop, just the way their father does it.They find a letter addressed to "J.W.". They are startled by the surprise appearance of their father. Reading the letter, John realizes that Elkins had been holding out on him about a legendary gun, a Colt made in 1835. He tells them it's Vampires, and they will hunt them together.

Sam is bridling at John’s dominating attitude and is constantly questioning his father's orders. Dean is frustrated by the reoccurring old arguments that drove the family apart. Working together to attack the Vampire nest and look for the Colt, they are discovered before John can grab the gun, and end up running for their lives. John has alternative plan and while waiting for Dean to return with dead man’s blood, Sam and John talk, mending fences in the process.

They use the dead man’s blood to catch Kate in order to draw out Luther, her Mate. John’s plan is to trade her for the Colt. While Luther and his vampires discover John and Kate and parley for the Colt, Sam and Dean invade the nest,  freeing the captives. John’s plan is foiled and he is knocked out by Luther, however before Luther can kill him, Sam and Dean attack, having ignored their father's orders to stay away. John, grabbing the Colt, kills Luther by shooting him in the head. The gun works. It can kill supernatural beings with a bullet. Finally seeing the sense of the boys argument, John agrees that now they have the Colt, they will hunt the Demon together.

Blue Earth, Minnesota – A priest is reading the Bible at his Alter. Meg enters as a young woman seeking solace. The priest encourages her to speak but, when he sees her black eyes, the priest retreats in horror to an underground office. She demands the Winchesters who he refuses to betray. She slits his throat.

Back in Manning, Colorado, John is sharing his research of the last 20 years with Sam and Dean. John sees the signs starting again and is intent on saving another family from the pain and loss suffered by the Winchesters. The 3 hunters head out to Salvation, Iowa. On the road, John receives the news that Pastor Jim Murphy has been murdered. John feels the pressure to hurry, to find the next family on the demons list. Following the signs in his vision, Sam meets the young mother Monica and her daughter, Rosie. Unable to warn her, he returns to Dean and John. Sam’s phone rings and Meg, demands to speak with John. Informing him that she murdered Jim Murphy and today she is with Caleb. She wants The Colt.In desperation John plays dumb and Meg kills Caleb. John offers her the Colt, but he has a plan. To substitute a fake colt for the real one. 

 While the boys stand watch over Monica and her family, John confronts Meg. She is joined by another demon. John hands the gun to Meg and she in turn hands it off to the other, asking if they think it’s the real thing? Without warning he shoots Meg. Now it is obvious the gun isn’t the real Colt. Making his escape John finds his truck’s tires have been slashed. Running, he finds himself in a dead end and trapped.

Meanwhile, recognizing the signs, the boys break into the house in attempt to save Monica and Rosie. Racing to the nursery Sam faces the demon over Rosie’s crib a, fires off a shot but the demon vanishes. They race them from the burning house. Dean stops Sam from trying to reenter the burning building to reach the demon. Back at the hotel room, Dean tries his father’s phone, it is answered by Meg and to their horror she promises they will never see their father again…

The boys arrive at the home of another hunter, Bobby. Sam goes through some of Bobby's books on demon lore, including the Key of Solomon, while Bobby and Dean talk. Suddenly Meg kicks in the door, attacks the boys, and demands the Colt. However, she soon gets caught under a devil's trap that is painted on the ceiling. Bobby explains that Meg is actually a girl possessed by a demon, and that the injuries she previously sustained in Chicago (in the episode 'Shadow') will kill her if the demon leaves her body. Dean insists on exorcising the demon to save the girl, no matter how broken she is. Finally, the demon is banished, and human Meg, dying painfully, thanks them and offers the clue "sunrise." 

They arrive at the building where John is being kept, form a plan to evacuate it that involves dressing up as firemen, and execute it. They manage to overpower the possessed humans guarding John and get him out of the apartment - after Sam insists on testing John with holy water. John is barely coherent, but he manages to ask about the Colt. Once all three are out of the building, they're set upon by Tom, who beats Sam severely. Dean whips out the concealed Colt and shoots him through the head.

In a secluded cabin, the boys salt the doors and windows. John enters, claiming that Dean should be proud of what he does for the family. Dean grows suspicious of the kind words and points the Colt at John. Sam allies himself with Dean, and John is revealed to be possessed by the Demon as his eyes glow yellow. The Demon injures both boys and taunts Sam's unreliable special powers, and he also mentions that Sam was about to propose to Jessica. Dean draws the Demon's attention away from Sam, and it reveals that the demons in Meg and Tom were his children. He uses some psychic power to attack Dean, causing him to bleed internally. Dean begs for his life, and John manages to surface long enough for Sam to free himself and grab the Colt. John begs Sam to kill him in order to kill the Demon while Dean pleads for Sam not to shoot. Sam uses the penultimate bullet in the Colt to shoot John in the leg, forcing the Demon to leave John's body.

Sam drives the Impala with John in the passenger seat and Dean, gravely hurt, in the backseat. John expresses disappointment that Sam didn't shoot and end the family's quest, but Sam says that killing the Demon is not the most important thing. Sam promises to get them to the hospital, but a huge truck slams into the Impala, smashing it and rendering all three Winchesters unconscious. The truck driver has the black eyes of the possessed.

The boys arrive in Chicago to investigate recent violent deaths. Disguised as operators from a security alarm company, they visit the apartment of the last victim. Dean notices that the blood spatter on the carpet forms a symbol.

That night they visit the bar where Meredith worked. Sam spots a familiar face; Meg, the girl he met when he was going to travel to California to find John. Sam tracks Meg to an abandoned warehouse, where he observes her at an altar, communicating with someone through a goblet of blood. Dean calls John and asks him to come to Chicago. 

At the abandoned warehouse, the boys’ plans are thwarted when Meg commands to daeveas to attack them. Once they are restrained, bound to pylons, Meg reveals the murders were a plan to trap them, and use them as bait for John. Sam cuts himself loose and overpowers Meg and then overturns the altar. Freed from her control the daevas turn on Meg, and throw her from the window. Sam and Dean see her dead on the pavement beneath.

Returning to their room, Sam and Dean find an unexpected visitor – John. Their reunion is interrupted when the daevas attack them, but Sam repels them by lighting flares. As they go their separate ways, they are observed by a figure in the shadows – Meg.

A group of teenagers in Richardson, Texas, visit a reputedly haunted house,they find the body of a girl hanging in the cellar. However, by the time the police arrive, the body is missing.Sam and Dean, who are engaged in a prank war, decide to investigate and track down Craig Thursten, who relates the legend, of Mordechai Murdoch, a farmer who lived in the house during the 1930s, and who killed his daughters, hanging them in the cellar.

Sam and Dean visit the house, which has symbols painted from many different origins freshly painted on the walls and floor. While searching the house, the boys run into Ed Zeddmore and Harry Spengler, paranormal investigators, who run a website called Hell Hound's Lair. Mordechai chases them from the house and is not slowed by a blast of rock-salt. Dean and Sam return to visit Craig. Craig admits that he and his cousin painted the symbols and spread the rumour about Mordecai as a prank. Sam postulates that Mordecai is a Tulpa – the manifestation of a thought. One of the symbols painted in the house is Tibetan spirit sigil, which assists in concentrating mental energy. In order to “kill off” Mordechai, the boys tell Ed and Harry that they have found out that being shot with iron rounds will kill him. They wait for the boys to post it on their website, and enough people view it so that it becomes real. Ed and Harry tell them the server crashed, so the new legend will not manifest. As Mordechai attacks them, Dean sets the house on fire, figuring that without that part of the legend Mordechai won’t exist.

In Fitchburg, Wisconsin children in the town are becoming mysteriously ill. Dr Hydeker at the local hospital indicates that no treatments are proving effective with the children, who seem to have compromised immune systems.At the home of the latest victim, the boys find an inhuman handprint on the window ledge outside the child’s bedroom. After checking into a motel run by a woman with two young sons, Michael and Asher, Dean tells Sam he thinks the creature at work is a shtriga, which their father had encountered many years previously. Back at the motel, the youngest child Asher is sick and has been taken to hospital. While Dean drives the mother to the hospital and interviews the doctor again, Sam finds the Shtriga is disguised as Doctor Hydecker - who is working at the hospital in Fitchburg, and is also seen in an 1890s photo.

Dean says John found out they are vulnerable when feeding. Sensing Dean knows more about the shtriga than he has revealed, Sam pushes him. Sixteen or seventeen years ago, John Winchester was hunting a shtriga in Fort Douglas, Wisconsin. While John was out, Dean left Sam alone briefly and the shtriga attacked. John shoots it and takes the boys to stay with Pastor Jim, but when he returned he couldn't track the shtriga. Dean blames himself for its escape, and for the deaths that have occurred since. Dean suggests using Michael as bait to trap the shtriga. Michael at first refuses, but later decides to do it, even though Dean can't guarantee Asher will get better. Dean and Sam set up a system to observe Michael in bed, as they need to wait until the shtriga starts feeding before they can attack. The Shtriga attacks Michael and the boys storm in, only killing the monster when it tries to feed on Sam.After the Shtriga is killed, Asher and the other children recover.

The boys arrive in upstate New York, where Mark and Anne Telesca were found dead in a locked house, the latest in a series of murders over a number of decades in the same area according to research from John’s journal. They visit the Telesca home, but all the furnishings have been taken to an auction house, so they decide to check it out, in case a spirit has itself attached to an object. Sarah Blake, who works at the auction house confirms that the Telesca estate is being auctioned. Before she can tell them anymore, her father asks the boys to leave.

Over dinner, Sarah reveals she hasn’t been on a date since her mother died unexpectedly a year ago.Sarah get’s Sam copies of the provenances of the items of the Telesca house. Dean finds that a portrait of Isaiah Merchant’s family painted in 1910 was also owned by the other families which had been killed. At the local library, they find out that Isaiah Merchant was accused of killing his wife, two sons and adopted daughter. Sam calls Sarah to see if they can view the painting again, only to find it has been sold, to a friend. The boys rush to the house just as Sarah arrives, and they find Evelyn dead, her throat slashed. They examine the painting and more features in the painting have changed, amongst other things there is now a mausoleum in the picture with the name Merchant on it. Sam and Sarah get trapped inside Evelyn’s house, and attacked by the spirit of Melanie Merchant, the adopted daughter. Dean returns to the mausoleum and burns an antique doll which bears some of Melanie Merchant’s hair. This finally dispels her spirit.

Episode - 12 [Faith]

Episode - 14 [Nightmare]

Episode - 10 [Asylum]
Sam and Dean receive a tip from their father, and travel to Rockford, Illinois, to investigate the haunted Roosevelt Asylum, where criminally insane patients rioted in 1964. One of the riot's victims was the chief psychiatrist (Norman Armour). The spirits there try to communicate rather than attack, leading the brothers to discover that the psychiatrist had been conducting cruel experiments on his patients in order to test his theory that provoking extreme anger would be therapeutic for them. The ghost of the doctor then confronts Sam, causing him to lose his sanity and try to kill his brother. Dean manages to subdue Sam and burn the doctor's corpse, stopping the spirit and returning Sam to normal. 

After Zach (Aleks Holtz), a college friend of Sam's, is arrested for murdering his girlfriend, the brothers head to St. Louis, Missouri, to investigate. Zach's sister Becky (Amy Grabow) claims that he was with her at the time of the murder, although security footage places him at the scene of the crime. After a similar murder occurs, they realize that the real culprit is a being with shapeshifting abilities. The shape-shifter then captures the two, and plans to use Dean's form to kill Becky. The brothers escape and alert the police. Becky is saved, but the police believe Dean to be her attacker. As Dean later searches through the shapeshifter's lair, Sam visits Becky to make sure that she knows what they are dealing with. However, she reveals herself to be the shapeshifter and knocks Sam unconscious before morphing back into Dean. After the real Dean finds the Becky tied up in the lair, he confronts the shapeshifter and shoots it dead—still in his form.