The Only Supernatural Refresher You Need Ahead of Season 15

2005 was wild. It was the year that both Destiny's Child and Blink-182 announced their respective breakups, Carrie Underwood won American Idol, and Kanye West went off-script during a Hurricane Katrina telethon to memorably state, "George Bush doesn't care about black people." That same year, Supernatural, Eric Kripke's darkly fun series about two brothers who hunt demons for a living, debuted on The WB (which would merge with UPN to become the CW in the next year).

Supernatural has been around longer than the iPhone and in that time has amassed one of television's most dedicated audiences thanks to its charming leads, Jensen Ackles. Jared Padalecki, Misha Collins, and later, Alexander Calvert. It's hard to imagine The CW without the occult series but that's a reality we'll soon have to face with the show poised to end after Season 15, which premieres Thursday, Oct. 10 at 8/7c. With Sam and Dean's epic journey winding down, we're looking back at the tumultuous and unforgettable road they've traveled so far. Ahead of the final season, here's a refresher on everything that's gone down with the Winchesters.

Everything We Know about Supernatural Season 15

Season 1

Sam Winchester (Padalecki) thought he left the world of demon hunting behind -- he was living a normal life and gearing up for law school -- but then his brother, Dean (Ackles), drops in to inform him that their father, John (Jeffrey Dean Morgan), who's been hunting evil for 22 years, has gone missing. It's not until the death of Sam's girlfriend, Jessica (Adrianne Palicki), at the hands of Yellow Eyes, the demon that also killed their mother, Mary (Samantha Smith), that Sam jumps right back into the family business indefinitely. In their quest to track down the creature that ripped their family apart, the Winchesters encounter a variety of monsters along the way, including wendigos and shapeshifters. They eventually find Yellow Eyes (real name Azazel), who has possessed their father. But rather than kill John, Sam uses the family Colt, a special gun that can kill any supernatural creature, to shoot him in the leg, which expels the demon from John's body. En route to the hospital, Dean, Sam, and John are struck by semi-truck driven by a demon-possessed person.

Season 2

The crash at the end of Season 2 lands Dean in a coma and close to death. A desperate John strikes a deal with Azazel to save Dean's life in exchange for his own and the Colt, and the demon follows through. After making peace with his sons, John dies which sends Sam and Dean on a journey to hunt down the demon that has now claimed their father in addition to their mother and Sam's girlfriend. Along the way, they run into Bobby Singer (Jim Beaver), a fellow hunter and an old friend of John's who becomes a useful alley. Things come to a head when Sam is killed by one of Azazel's followers, which leads to Dean selling his soul to a crossroads demon in order to resurrect his brother. Dean has one year before it collects on his offer. The reunited brothers team up to kill Azazel once and for all, but not before inadvertently releasing hundreds of demons in the process.

Season 3

In the wake of Azazel's death, Sam and Dean track down the demons that have been released from hell, which is a tall order. They team up with a demon named Ruby (Katie Cassidy) who claims she can help Dean get out of his deal with the crossroads demon, adding that she also wants to protect them from the demonic leader Lilith, and becomes a reluctant ally. This season puts them in the path of interesting new creatures, like the Trickster (Richard Speight Jr.), who traps Sam in a nightmarish loop that forces him to watch Dean die over and over again. They also run into Bela Talbot (Lauren Cohan), a thief of the occult who is often at odds with the Winchesters. In a final showdown with Lilith, Dean is mauled to death by hellhounds and his soul is sent to hell.

Season 4

This season introduces Castiel, the rigid, trenchcoat-wearing angel who takes everything literally and doesn't understand human behavior. Angels have returned to Earth for the first time in several millennia to stop demons from helping Lucifer (Mark Pellegrino) escape from Hell, a charge led by Lilith. Sam and Dean found themselves at odds over Dean's mistrust of Sam's alliance with Ruby (Genevieve Cortese), who convinces Sam to drink demon blood in order to get strong enough to defeat Lilith. They also meet Chuck (Rob Benedict), a novelist who turns out to be one of God's prophets. The Winchesters eventually come face to face with Lilith who, with help from Ruby, goads Sam into killing Lilith which breaks the final seal that frees Lucifer from his cage in hell. The brothers then kill Ruby after she reveals that she's been working with the Devil all along, but it's too late. He's out and ready to cause trouble.

Season 5

The Winchesters set out to take down Lucifer, who is planning to bring about the Apocalypse via the Four Horsemen. They learn that the only way to stop him is by allowing the archangel Michael, who is Lucifer's brother, to possess Dean. It's the season we also meet a young Mary and John Winchester when fallen angel Anna travels back in time to prevent Sam's conception as an alternate way to stop Lucifer. In the same way that Dean is Michael's perfect vessel, Sam is revealed to be perfectly suited for Lucifer, which inspires a new plan. Sam allows Lucifer to possess him so that he can lock Lucifer back in the cage, but things go awry when Lucifer murders Castiel and Bobby. Sam regains control of his body long enough to drag both Lucifer and Michael to hell. Castiel is resurrected and he brings back Bobby, but Sam remains trapped in hell. In the aftermath, Dean decides to live a normal life with his girlfriend Lisa and her son Ben.

Season 6

Picking up a year later, Sam is somehow freed from hell without his soul and Dean leaves behind his normal life to rejoin the family business. Sam has been working with their grandfather Samuel, who has actually been working with the demon Crowley (Mark Sheppard), the current King of Hell. Meanwhile, Castiel is preoccupied with a civil war in heaven spurred by the archangel Raphael's (Demore Barnes) desire to take over so he can free Michael and Lucifer and start the Apocalypse. In an effort to help Sam, who has become a different person after returning from Hell, Dean makes a deal with the Horseman of Death to retrieve his soul. However, it also restores painful and traumatic memories of his time in the underworld, so Death puts up a mental barricade so that Sam won't remember, which Castiel knocks down when the Winchesters and Bobby try to stop his deal with Crowley to split the souls of Purgatory among themselves. Castiel then turns on Crowley and absorbs most of the souls from Purgatory, which makes him all-powerful. After killing Raphael, he declares himself the new God.

Season 7

Drunk on his new power, Castiel abandons Sam and Dean to rule heaven. Later, we find out his mind was being controlled by the Leviathans, the biggest threat that Sam and Dean would face to date. They were the first beings God created but were locked away in Purgatory for being too destructive. It was a season of loss for the Winchesters, with Bobby dying and becoming a vengeful spirit before Sam and Dean put him to rest. Plus, Sam was left all alone when Dean and Cas wound up in Purgatory and Crowley abducted their friends Kevin (Osric Chau) and Meg (Rachel Miner). Back-to-back tragedies proved to be too much for the younger Winchester, who quit the hunting game altogether.

Season 8

A year later, Dean escapes Hell with help from his new vampire friend, Benny (Ty Olsson). His relationship with Sam becomes strained, with Dean angry that Sam retired from hunting and Sam upset he let a vampire live. Meanwhile, Castiel is freed from Purgatory by a powerful angel named Naomi (Amanda Tapping) who has taken over heaven. This season, we're introduced to the Men of Letters bunker and the Metatron (Curtis Armstrong), God's scribe who tells Sam and Dean about an angel table that can seal heaven shut. Sam endures a series of trials to close the gates of Hell, not knowing he'll die upon completion. Fortunately, Sam passes out before that happens but the Metatron carries out his nefarious plan to essentially break Heaven. After the Metatron steals Castiel's grace, thus rendering him human, Cas is forced to watch helplessly alongside Sam, Dean, Bobby, and Crowley as angels fall to the earth.

Season 9

Things are pretty dire for Sam, who falls into a coma from the effects of the trials to close the gates of Hell and nearly dies. With Castiel out of commission after losing his grace, Dean turns to the angel Ezekiel (Tahmoh Penikett) who can only heal Sam's wound by possessing him. Knowing Sam would never go for it on his own, Dean and Ezekiel trick Sam into consenting to the possession without his knowledge. The temporary fix allows Sam and Dean to get back to hunting and figure out how to get the angels back in heaven with help from old friends like Charlie (Felicia Day) and Jody Mills (Kim Rhodes). Plus, they must also deal with the demon Abaddon (Alaina Huffman), who wants to take over Hell in Crowley's place (Crrowley is now a prisoner of the Winchesters). Elsewhere, Castiel is on the run from angels who blame him for their fall and restores his power by stealing another angel's grace. The Metatron returns to Earth and strikes a deal with Ezekiel, who turns out to be disgraced angel Gaddreel, to rebuild heaven together. Before Dean can warn Sam, Gadreel gains full control of Sam's body and kills Kevin, forcing Dean and Castiel to team with Crowley to expel Gadreel from Sam's body. Sam, returned to normal, is furious with Dean for his deception and the brothers wound up at odds in the wake of their friend's death. Dean again joins forces with Crowley to track down Abaddon and along the way, acquires the mark of Cain which gives him super strength along with an unrelenting desire to kill. Castiel tricks the Metatron and regains control of Heaven but only after the Metatron murders Dean in cold blood. Crowley resurrects him as a demon, much to Sam's surprise. Season 9 also tried, unsuccessfully, to launch its first spin-off, Supernatural: Bloodlines starring The Originals alum Nathaniel Buzolic.

Season 10

The pressure is on for Sam to find his missing brother, who was now a demon, while a weakened Castiel faces a grim future as his grace slowly drains from his vessel. The brothers eventually reunite, but Dean, still bearing the Mark of Cain, endures the consequences, which includes an insatiable lust for killing and uncontrollable rage. They turn to Rowena (Ruth Connell), Crowley's powerful witch mother, for help. But removing the mark proved to be more difficult than they imagined because doing so without finding a new host would unleash the Darkness, a primordial force that predates God. Death proposes a plan to send Dean somewhere where the Darkness will remain locked away, but only if he kills Sam. Unable to murder his brother, Dean chooses to kill Death instead. Rowena removes the mark, which unleashes the Darkness into the world. She also puts a dog attack spell on Castiel to kill her son Crowley, making Castiel more dangerous than ever.

Season 11

Sam reunites with Dean, who revealed that the Darkness, in the form of a woman in a black dress, thanked him for freeing her. It's also the season we first meet the reaper Billie (Lisa Berry), who drops an ominous warning on the Winchesters: the next time they die, she'll send them to the Big Empty, an endless void of nothingness. With Castiel still under an attack spell, the Winchesters turned to Rowena to remove it, and she eventually does. And after much speculation, the show finally confirms that Chuck is, indeed, God. The season ends with Dean gifted his resurrected mom Mary after convincing Amara to leave Earth instead of destroying it. However, tragedy strikes in the bunker when the British Men of Letters agent Toni Bevell banishes Castiel and shoots Sam, leaving his fate unknown.

Season 12

Upon his release from Hell, Lucifer (Mark Pellegrino) possesses different vessels, including a rock star named Vince Vincente (played by Rick Springfield), but finds that they burn out at faster rates due to his weakened state. Elsewhere, Dean and Mary team up with Castiel to track down Sam, who's being tortured by Toni Bell, who views the Winchesters as a threat and wants information on every hunter in the U.S. Dean Mary, and Cas eventually find Sam and stop Toni, returning to form hunting monsters of the week. Elsewhere, Lucifer begins possessing people of power including the President of the United States, Jefferson Rooney (David Chisum). While in control of Rooney's body, he conceives a powerful, Nephilim child with White House staffer Kelly Kline (Courtney Ford). Castiel, originally intending to kill both Kelly and her unborn son, becomes her caretaker and the kid's guardian. In a major showdown, Sam and Dean team with Crowley to send Lucifer to an alternate, apocalyptic world. Both Castiel and Crowley die in the process, however, but Mary is able to banish the Devil to the alternate world with her. While Dean mourns Castiel, Sam discovers Kelly's son Jack in teenage form.

Season 13

Sam and Dean deliver a hunter's funeral for Castiel and Kelly, while saying goodbye to Crowley and their mom Mary, who they believe is dead. Unbeknownst to them, Lucifer is keeping her alive in Apocalypse World. Meanwhile, Cas winds up in the Big Empty, a place that predates God and Amara, where angels and demon eternally rest after they die. Castiel is the first in eternity to awaken and is sent back to earth where he reunites with Sam and Dean. Adjusting back into a routine of hunting, Sam, Dean, and Castiel become surrogate fathers to Jack as he learns to control his limitless powers. It's the season which produced a backdoor pilot for a potential Wayward Sisters spin-off with Jody Mills and saw the show crossover with the animated seriesScooby-Doo for the instant classic, "ScoobyNatural." The Winchesters also embark on a mission to find Jack, who found Mary in Apocalypse World and has teamed up with an alternate version of Bobby to take down the archangel Michael. Sam and Dean lead a mission to bring Jack, Mary, Bobby and his group of hunters back into their world. Meanwhile, Lucifer and Michael team up to escape Apocalypse World, which leads to Lucifer stealing Jack's grace and rendering him powerless. In an effort to stop Lucifer once and for all, Dean allows Michael to possess him. However, once Lucifer dies, Michael takes full control of Dean's body and disappears.

Season 14

Michael possessing Dean forces a newly bearded Sam to step up as the sole leader of the pack while Dean fights for control of his body against the menacing archangel, who has launched an all-out assault on the Winchesters. Lucifer might be dead, but his vessel Nick remains alive and well, and goes to great lengths to find the deceased fallen angel but seemingly to no avail. Meanwhile, Castiel tries to help Jack adjust to life as a human, but Jack struggles with the idea of being helpless. This season saw the show reach its milestone 300th episode with a poignant hour in which John Winchester returned to offer up much-needed closure for Sam and Dean. Plus, Dean, having kept Michael at bay in his mind, loses control and Michael escapes and murders the remaining hunters in the bunker. Jack then kills Michael and inhales the archangel's grace, returning to full power. However, the gang is concerned because pieces of Jack's soul are burning away. A worried Mary confronts Jack, who kills her in a rage, leaving Sam and Dean at their wit's end about what to do with him (all while Casitel advocates for his conscience). Season 14 wrapped on a shocking note with Chuck turning on Sam and Dean when they refuse to kill Jack. In retaliation of the Winchesters' disobedience, Chuck murders Jack, sending him to the Big Empty, and unleashes hell on earth with the snap of a finger.

Supernatural returns for its 15th and final season Thursday, Oct. 10 at 8/7c on The CW.

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