Lenore tells to Dean, Sam, Bobby and Castiel that Eve is in a small town in Oregon and they head to hunt her down. Soon they discover that the locals have been transformed in hybrid species of demons and Dean calls them "Jefferson Starships". When they meet the Mother of All, they discover a secret about Crowley.
Sam, Dean, Bobby and Castiel track Eve to a small town in Oregon. The guys discover the townspeople have been converted to demons, but surprisingly, they all appear to be dying. When they finally do meet Eve, she decides to torture the brothers by bringing back their mother, Mary Winchester, as a demon.
- Two students, Todd Marshall and Ed Bright, leave a bar and find Eve waiting outside for them. They don't know who she really is, and she simply touches Ed and walks by as veins briefly spread across his face. Eve goes into the bar and locks the door behind her. One of the patrons notices blood on her dress and asks if she's okay. Eve approaches and kisses him, and the same pattern of veins spreads on his face. As Eve walks through the bar, touching more people, the first man goes berserk. The patrons begin attacking and biting each other while Eve picks up a drink and watches in satisfaction.
Bobby and the brothers load up five shotgun shells with the phoenix ashes, and Dean reveals that he got some on him and it didn't do anything to him. They speculate if that means it is powerless, and realize they have to find Eve first. Castiel appears and admits that Eve is shielded from angels, so Sam suggests that they find a friendly monster to help them. Castiel goes out and finally locates Lenore, the "friendly" vampire that they met several years ago. They ask her about Eve, and Lenore says that she is staying far away from her. She warns them that Eve influenced the other members of her nest, causing them to go out to kill, and explains that everyone gives in eventually. Dean suggests that she tell them where Eve is, and Lenore warns that Eve can see through her. Sam appeals to her better nature, saying that Lenore can't want the entire planet dead, and Lenore tells them that Eve is in Grants Pass, Oregon, and Eve knows that they're coming for her. However, Lenore says that she needs something; she asks them to kill her because she's exactly like the others, and she fed on a 16-year-old girl. Sam hesitates, but Castiel reaches forward and burns her dead with a touch.
Castiel teleports Bobby and the Winchesters to Grants Pass, but find nothing amiss. They go to a diner and Bobby accesses the police department computer base, and finds nothing. Castiel tries to teleport away to search the town and realizes that he's blocked. Bobby learns that Ed Bright's doctor, Silver, called the CDC. Dean and Castiel go his office and discover that he's disappeared. As Dean picks the lock of the office, they spot blood on Silver's shed and finds Ed Bright's corpse inside. Dean prepares to burn it.
Bobby and Sam go to Silver's home and confirm that the house is empty, and that he had a wife and two sons. They run into the local sheriff and claim to be FBI agents, and the sheriff says that he's there to see if Silver is sick. Bobby successfully bluffs the sheriff into putting out an APB back at the station. Dean and Castiel arrive and Castiel points out that Ed Bright is in a nearby house. Sam and Dean break in and find several Ed Brights. Most of them are dead, but one of them is dying. He says that he's not dead, and they check his ID and confirm that he's Todd Marshall, Ed's friend. Todd asks if they all look like Ed, and they assure him that he's hallucinating. He tells them that they were at a bar, gives them the address, and says that a girl in white was there. Todd dies before he can say anything further.
The four men go to the bar and find everyone dead. One of them is a vampire but has a wraith spike, and they realize that Eve is creating hybrids. As the person discovering them, Dean names them Jefferson Starships. Bobby concludes that they have all burned out. As they talk, the sheriff and his deputies arrive and arrest Sam, Bobby, and Castiel, while Dean hides behind the bar.
At the sheriff's office, Sam catches a glimpse of the officers in the surveillance mirrors and realizes that they're Starships. They start to fight back and Dean arrives in time to kill all of them except the sheriff. They capture him and take him to an interrogation room, but he refuses to answer bobby's questions. They hear a banging noise outside and realize that more Starships are attacking. Sam and Dean go to investigate and find Silver's two children locked up in a cell. The Winchesters free them and the brothers introduce themselves as Joe and Ryan. Ryan, the younger one, won't talk and Joe explains that his brother can't talk since they came for them. Dean says that they'll free them as soon as they confirm their human.
Sam and Dean bring Joe and Ryan back to the office, give them food, and ask them what they know. Joe explains that the creatures were holding them for food. Dean promises that he'll take the boys to their uncle, fifteen miles away, but Castiel calls him aside and says that they have to worry about the greater purpose. Dean refuses and tells him to wait while he and Sam get the Silver brothers to safety. As they drive, Joe watches over his little brother as Dean looks on.
At the sheriff's office, Castiel tells Bobby that it was a bad idea letting Sam and Dean go. Bobby warns him that no one lets the Winchesters do anything, and suggests they interrogate the sheriff again.
Sam and Dean drop the Silver brothers off with their uncle and then leave.
The sheriff warns Bobby that eve can see them through him. Castiel asks for five minutes alone with the creature and Bobby reluctantly agrees. Bobby then waits in the office and hears the sheriff screaming. Castiel comes out and tells Bobby where Eve is holed up, and tells him to call Sam and Dean with the information.
Dean and Sam return and discover that Castiel has decapitated the sheriff. They each take on shotgun shell and go to the diner where they were earlier. Dean says that he and Sam will go in to draw Eve out, and Castiel and Bobby will back them up. The brothers go inside, walk past the customers, and sit down. Sam uses his camera and confirms that everyone in the diner is a Starship. Eve, dressed as a waitress, offers them food and they realize who she is. The Starships lock the doors, draw the blinds, and relieve Sam and Dean of their guns. She realizes that they have phoenix ash and tells her minions to destroy the guns, and then explains that she's not there to fight. When they ask what she wants, Eve explains that she preferred the original arrangement, where hunters and monsters had a balance. But then Samuel and his people started abducting her children, and she pushed back.
When Dean and Sam don't believe her, Eve takes on the form of Mary Winchester to emphasize her point about a mother's love. Dean tells her to kill them and be done with it, but Eve says that she wants Crowley, who's not dead. She explains that he's still abducting her children, and he's using their souls as power, siphoning off her supply. If she can't stop Crowley, then she'll convert everyone Earth to bolster her forces. Grants Pass is her laboratory to build the perfect monster. Eve admits that there were a few failures, but she's perfected the process. Smiling, she tells them that she used the brothers as the ultimate test: Ryan was one of the creatures.
Joe's uncle finds Joe dead on the floor, his neck ripped out. Ryan comes out, covered in blood, and Joe comes back to life. The two creatures attack the uncle, killing him.
The brothers are less than thrilled that Eve has played them. She offers them a proposal: they bring her Crowley and she lets them leave. Dean immediately refuses, and Eve points out that he has no other options. Her creatures bring in Castiel and Bobby, and Eve explains that she's far older than any angel and she knows how to negate his powers. She repeats her offer, but Dean insists that they don't work with monsters and dares her to kill them. Eve says that she'll turn them instead and Dean still refuses. She grabs him and says not to test her, and Dean tells her to bite him. She does, but then falls back, gagging, as Dean explains that he drank the phoenix ash down with whiskey. They watch as Eve burns up from the inside and collapses to the ground. The creatures start to attack and Castiel, his powers restored, destroys them all and then heals Dean's neck wound.
Dean immediately insists on going to save Ryan and Joe. Disgusted, Castiel agrees and teleports them to the house, and they find the uncle, dead. Joe and Ryan are in the basement, dead, and Sam finds traces of sulphur, indicating that demons are responsible. Dean and Sam tell Castiel what Eve told them about Crowley, and the angel says that he'll look into it immediately and teleport away. Once he's gone, Bobby wonders how Castiel screwed up, and suggests that Castiel let Crowley get away. Dean doesn't believe it, but Sam isn't so sure.
Castiel goes to the diner and finds Crowley waiting for him. Crowley says he's tired of cleaning up after his messes.