Sunrise, Wyoming: March 5, 1861
The townspeople watch as two men step out into the middle of the street. One of them is Dean. The two men draw and fire.
48 Hours Earlier and 150 Years Later
Dean, Sam, and Bobby search the Campbell compound and find a hidden chamber with books on arcane lore. They look for ways to kill Eve and find a reference to the ashes of the phoenix. Finally they find a reference to Colt's gun using the phoenix ashes in 1861 at Sunrise, Wyoming, to destroy a monster... in Samuel Colt's own journal. Dean figures they can go back in time and calls upon Castiel. Another angel, Rachel, arrives on Castiel's behalf and explains that he is busy. She isn't impressed with the urgency and accuses them of only calling Castiel when they need him. Rachel starts ranting at them, but Castiel arrives and tells her to leave. Once she leaves, Castiel explains that Rachel is his lieutenant and committed to the cause.
The Winchesters explain what they need and Dean goes on a supply run. Castiel warns that they only have 24 hours, and the further he sends them back, the harder it is to retrieve them. Dean arrives with Western clothing and insists that they'll have to wear it. Sam objects, noting that his brother is obsessed with Western movies, but reluctantly agrees. After Bobby provides them with gold and jewelry to use as cash, Castiel then sends them to 1861 and then tells Bobby to pray for him in 24 hours and he'll return.
Sam sets the timer on his watch and they head into town to find a saloon. They arrive to see the townsfolk hanging Elias Finch, a man who murdered his wife. The judge, Tye Mortimer, passes sentence and Elias tells them that they'll all burn for killing him. Unimpressed, the executioner pulls the lever and hangs Elias. Afterward, the brothers approach the sheriff and claim to be lawmen. The sheriff has no idea where Colt is, and tells them to talk to the saloon keeper, Elkins. At the saloon, they talk to Elkins, who says that Colt is busy at the site where they know the Devil's Trap will be built, 20 miles away. A prostitute, Darla, hits on Dean, but Judge Mortimer arrives and interrupts them to take Darla on their "date."
While Sam and Dean drink, Mortimer gets into bed with Darla. She looks up in horror and screams, and runs to the door, while Finch grabs the judge's chest and incinerates him. The Winchesters hear the scream and run upstairs, and find nothing but ash. The sheriff arrives to investigate, noting that the killer left footprints. Darla says that she saw Elias, and the sheriff figures that the rope didn't kill him. He gathers a posse for the next morning and asks Sam and Dean to come with them. They readily agree, and then go to the cemetery. They discover that Finch has broken out of his grave, and wonder if Finch is the phoenix they're looking for. Dean suggests that Sam find Colt and get the gun so they can use it to kill Finch. Sam reluctantly mounts up and gallops away.
The sheriff is preparing to leave when his horse starts bucking. Finch emerges from the shadows and the sheriff shoots him without effect. He begs for Finch's forgiveness, but Finch grabs him and reduces him to ash.
Rachel summons Castiel to a warehouse and asks if what she's been hearing about his secret is true. He insists that he has to defeat Raphael, but Rachel warns him that he's turning into something different. Castiel says that he doesn't have a choice and Rachel attacks him with an angel-killing knife. He manages to stab and kill her, and then clutches at the wound she inflicted on him. He gets back to Bobby's house and inscribes a rune on the refrigerator in his own blood before collapsing.
Dean returns to the saloon the next morning and learns that the sheriff is dead. Elkins picks up the sheriff's badge and pins it on Dean.
Two demons track Colt to his cabin, and he tells them that he's too old to be looking for any trouble. They want him to open the Devil's Gate and Colt tells them to walk away. When they refuse, he draws and kills them.
Dean goes to the deputy's room and asks why he wasn't at the posse. The deputy is packing to leave and Dean points out that Finch said the deputy would be his third victim. He wants the deputy as bait.
Sam arrives at Colt's cabin and explains to the gunsmith that he's a hunter from the year 2011. Colt asks for proof and readily accepts Sam's cell phone as evidence, but isn't impressed. Sam shows him his journal from the future and explains that he'll shoot a phoenix in three hours. Colt says that he's retired, and Sam says that he's a hero in 2011 and they need to kill the phoenix to use the ashes to kill Eve. When it's clear Colt won't come with him, Sam asks for the gun, and Colt tells him he lost it in a game of poker. Sam knows that he's lying, having seen the demon footprints and smelled the sulphur. However, Colt warns that it's a curse and won't turn it over.
With an hour remaining, Castiel wakes up and claims that Rachel betrayed him to Raphael. He explains that the rune is a warding symbol against angels, and that he'll soon heal. However, Castiel tells Bobby that in his weakened condition, he can't bring Sam and Dean back. When Bobby asks what he can use to power himself up, Castiel explains that he can touch Bobby's soul and use the energy to bring the brothers back. However, it's a delicate procedure and if he doesn't do it just right, Bobby will explode. Bobby agrees.
Dean takes the deputy to the jail and locks him up. As it draws close to noon, Dean asks the deputy why Finch wants personal revenge. Finch comes in and Dean invites him to break open the cell. When Finch hesitates, Dean figures that the iron in the bars repels him and tosses him an iron nail to confirm that Finch is vulnerable to iron. Finch tells Dean that he was married to a human woman and didn't bother anyone. The deputy raped his wife, shot him, and then shot the wife. The sheriff put him in iron shackles, allowing them to hang him. Dean demands the truth from the deputy, whose silence speaks volumes. Finch asks if Dean is willing to die to protect the man, and Dean says that he has no choice but to kill Finch. Finch grabs a gun and shoots the deputy, and Dean leaps out the window.
On the street, Finch hunts down Dean, who hides in an alleyway. Sam arrives and explains that Colt wouldn't come, but gave him the gun. He gives it to Dean.
With two minutes left, Castiel prepares to touch Bobby's soul.
Dean goes out onto the street and calls Finch out. They open fire, and Dean shoots and kills Finch, who explodes into ashes. Dean and Sam run to grab the ashes... just as Castiel pulls them back to the present. Castiel is in no condition to send them back. There's a knock on the door and a delivery man arrives with a package. He says that someone left a package for Sam with a note saying it there today. It's from Samuel Colt. Sam takes it and opens it with the others. Inside is Sam's cell phone and a bottle of the phoenix ashes. Dean figures that now they can take the fight to Eve.