Yellow Fever
Production information
Season : 4
Episode : 6
Original airdate : 23 October, 2008
Directed by : Phil Sgriccia
Written by : Andrew Dabb
Daniel Loflin
Preceded by : Monster Movie
Followed by : It's the Great Pumpkin, Sam Winchester

Yellow Fever is the sixth episode of Season 4 of Supernatural.


"Hell beckons again when Dean is stricken with a mysterious illness that frightens its sufferers to death. Sam and Dean scramble to find the cause in time to save Dean from sure death."[1]

Full synopsisEdit

Sam and Dean are investigating a series of three deaths in Rock Ridge, Colorado, wherein all of the healthy male victims suffered two days of intensifying fear and paranoia which ultimately led to heart failure; the first of the deaths being Frank O'Brien. During an autopsy that the boys insist upon, the coroner finds no arterial blockages in Frank's system, and the only thing wrong with him is that his right arm is badly scratched up.

Sam and Dean next see each of Frank's friends to ask how he was before his death: first the eccentric, midly-germaphobic sheriff Al Britton, then the reptile-loving Mark Hutchins. Both of them confirm, whilst Dean begin to act somewhat more unnerved and out of sorts than usual, that Frank had been acting strangely. Mark also mentions that Frank used to be a bully in high school, but he "got better," particularly after his wife Jessie committed suicide in 1998.

The following night, Dean's nervy and paranoid behaviour continues to escalate, and the boys eventually discover that Dean is haunted when he sets off the EMF meter. The boys call Bobby, who diagnoses that Dean has contracted ghost sickness; in which a spirit turns fear into a contagion which infects the living, causing the fear, paranoia and nerves to intensify increasingly, until it gets to such a point where their heart gives out 48 hours after infection. Dean got infected from Frank O'Brien's body, but only some people get infected because it afflicts those who use fear as a weapon in some way, or were "all dicks." Bobby has also theorised that if the ghost from whom the infection originated is put to rest, then the ghost sickness should clear up.

Later in the day, whilst a paranoid Dean is alone in the motel room, he begins to hallucinate; being driven mad by the ticking of a clock and by words out of a book seemingly taunting him about his impending death if the ghost sickness isn't cured. Dean also unexpectedly coughs up a wood chip once Sam gets back, and Sam realises that the ghost sickness's symptoms are echoing and communicating information about the original spirit. The boys go to investigate the abandoned Cassity & Sons Lumber Mill; there (after Dean has a big scare with a cat), the boys find an ID card for a Luther Garland, along with many drawings of Jessie O'Brien. They're then attacked by a giant, lumbering Luther's ghost, at which Dean flees in terror.

Afterwards, Sam and Dean (who is now very panicky about people discovering their IDs are fake) look into Luther Garland, and find that it only says he died of "physical trauma" and that there was no further police investigation; meanwhile, the sheriff, who apparently covered up Luther's death, is himself infected with ghost sickness and going insanely paranoid that "they know." Sam and Dean go to Luther's brother John at the Peaceful Pines Assisted Living home, and he tells them the real story about how his brother died: Luther was in fact ostracised by everyone in town for his gigantic stature, despite the very kind soul he had underneath - everyone except Jessie O'Brien, who was kind to Luther and whom Luther had a crush on. When Jessie vanished, Frank O'Brien went after Luther and, finding Luther's drawings of her at the mill, chained Luther by his neck to the back of a truck and drove it up and down the mill road.

Sam and Dean realise that the victims of the ghost sickness are experiencing Luther's death in slow motion, with the increasing terror and the worsening arm-scratches; but they're unable to simply put to Luther to rest with the usual salt-and-burn procedure since bits of him were likely torn off and scattered all over the mill road when he died. Meanwhile, Dean's ghost sickness symptoms are growing worse and worse - he at one point snaps outside the Impala and rants about the insanity of hunting ghosts and what they do. Then later, in the motel room, Dean briefly hallucinates Sam turning his eyes yellow and declaring that he isn't possessed but is going to become this, embracing his demonic side while Dean dies and goes back to Hell. At one point, Dean even runs through the streets in terror from a Yorkie dog as though it's a hellhound.

The next day, with two hours left to cure Dean before the ghost sickness kills him, Sam meets with Bobby, who identifies Luther's ghost as a buruburu, which can be put to rest with the same fear it died in and spreads; the two immediately head to the mill to deal with Luther. Meanwhile, as an insanely-panicked and -paranoid Dean remains cooped up in terror in his motel room, the sheriff suddenly breaks in and attacks, trying to kill Dean in his sickness-induced paranoia and admitting in his panicked rants that he covered up for Frank because he was his friend. However, Dean, hallucinating the sheriff as a demon because of his own ghost sickness, fights back, until the sheriff's heart gives out and he drops dead. Then Dean hallucinates Lilith (as she appeared in No Rest for the Wicked), who taunts him about the truth that he does remember Hell, and tells him to listen to his heart in overdrive; Dean begins to collapse, and literally has seconds left.

Back at the mill, Sam successfully lures Luther out by destroying his drawings of Jessie, then when he attacks Sam, Bobby wraps a spellwork-inscribed iron chain around Luther's neck, and drives the truck it is hooked to up and down the mill road, dragging Luther along - repeating his death and successfully neutralising his spirit in its terror. When Luther is dispatched, Dean instantly recovers from the ghost sickness at the very last second, and all the symptoms clear up.

Later, Sam and Dean are talking by the Impala. Sam asks Dean how bad his hallucinations got at the end and what it was he saw - Dean nearly tells Sam, but then for a moment he thinks he sees Sam's eyes flash yellow in the sunlight, and chooses to cover up the truth and simply say he saw howler monkeys.








  • This episode contains a small coda/outtake at the end which shows Jensen Ackles lip-syncing to Survivor's Eye of the Tiger in and on the Impala, based on a scene from the episode where Dean was doing so until he was interrupted by Sam.
  • The line of Japanese that Bobby speaks to Sam - "Kimi nanka umareru mae kara, zutto da yo" - translates to: "Since before you were born" (specifically, "Since before you were born, ya idjit," as explained by Jim Beaver in Supernatural: The Official Companion - Season 4).


  1. Supernatural: The Complete Fourth Season DVD episode guide
Supernatural Season 4
Lazarus RisingAre You There, God? It's Me, Dean WinchesterIn the BeginningMetamorphosisMonster MovieYellow FeverIt's the Great Pumpkin, Sam WinchesterWishful ThinkingI Know What You Did Last SummerHeaven and HellFamily RemainsCriss Angel Is a DouchebagAfter School SpecialSex and ViolenceDeath Takes a HolidayOn the Head of a PinIt's a Terrible LifeThe Monster at the End of This BookJump the SharkThe RaptureWhen the Levee BreaksLucifer Rising

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