What Supernatural Episode Does Dean Slip and Sent Back in Time

After 15 long years, Supernatural finally ended near the end of 2020. Over the course of 15 seasons, Supernatural's mythology became more complicated and convoluted, going through multiple showrunners and creative teams, which made it hard to remember every plot thread.

As Sam (Jared Padalecki) and Dean (Jensen Ackles) worked to avert multiple apocalypses, they did their best to make sure nothing went unresolved, but they didn't catch everything. So, in honor of 15 seasons, here are 15 unresolved Supernatural plotlines.

Cassie Robinson - Dean's first love (Season 1)

The first season of Supernatural featured some of the best monsters and moments, but one of the most personal plot points involved the introduction of Dean's first true love, Cassie Robinson (Megalyn Echikunwoke). Cassie only ever appeared in one episode ("Route 666"), but in that time, she helped the boys take down a racist ghost truck, and she made an impression.

Once the episode ends, Dean and Cassie say their goodbyes, with Dean confident that they'll meet again (and maybe even settle down). It seems that there may have originally been more plans for Cassie in the show's future (setting her up as Dean's "one true love"), making it odd that we never hear from her again. But that's the tragic love life of Dean Winchester.

Sam "coming back different" (Season 2)

After Sam was killed at the end of "All Hell Breaks Loose - Part 1", Dean makes a deal with a demon to bring his brother back and after Sam is resurrected (with some serious strings attached), they finally take out the Yellow-Eyed Demon (Fredric Lehne), but not before he warns them that everything might not be as it seems ("All Hell Breaks Loose - Part 2").

Azazel taunts Dean in the final moments before his death, asking how certain he is that what came back was "100% pure Sam". While demons certainly lie, the show doesn't explore this further. Sure, Sam ended up using his demonic powers in Season 4, but that didn't seem to be the "different" that Azazel was alluding to…

What happened to the other Deadly Sins? (Season 3)

After the Devil's Gate was opened, thousands of demons and ghosts were released from Hell, including the Seven Deadly Sins. According to Bobby Singer (Jim Beaver), the last time these demons were "topside" was during the Dark Ages ("The Magnificent Seven"). A few of the Sins were killed by Ruby (Katie Cassidy), but some of them lived another day.

Since Envy, Sloth, Lust, and Wrath all survived, it seemed like they'd eventually return, but they were forever a "no show". Given their apparent importance in the demonic hierarchy, it seems unlikely that the remaining four Sins wouldn't come back for revenge, especially when Hell was looking for a new King after Crowley (Mark A. Sheppard).

Jesse Turner - the missing Antichrist (Season 4)

When Lilith (Katherine Boecher) begins breaking the 66 Seals to free Lucifer (Mark Pellegrino) and start the Apocalypse, the angel Castiel (Misha Collins) reveals to Sam and Dean that the young Jesse Turner (Gattlin Griffith) would become the Antichrist ("I Believe The Children Are Our Future"). Cass says that "with a word," Jesse would destroy the heavenly host.

Throughout the show, both Lucifer's son, Jack Klein (Alexander Calvert), and even Sam have been referred to as "the Antichrist" due to their dark abilities, but Jesse, a half-human/half-demon cambion, was the real deal. Jesse's role was basically filled by Jack later on, so the supposed Antichrist was completely forgotten as the series continued.

What happened to the other Horsemen? (Season 5)

The Four Horsemen of the Apocalypse arrive in Season 5 to usher in Lucifer's arrival. The final Horseman, Death (Jullian Richings), would become a staple of the series (appearing until the end of Season 10), but his brothers, Famine (James Otis), Pestilence (Matt Frewer), and War (Titus Welliver), never made it past their introductions.

With their "power rings" still intact, fans have begged the question of why the remaining Horsemen never bothered to track down the Winchesters. It would have been easy to bring back these apocalyptic trailblazers, either to retrieve their rings or seek revenge against Team Free Will for foiling their plans (or maybe killing Death later on).

Is Ben Braeden actually Dean's son? (Season 6)

After first appearing in Season 3's "The Kids Are Alright", Dean has speculated that he is the father of the young Ben Braeden (Nicholas Elia), the son of his girlfriend Lisa (Cindy Sampson). In fact, Dean lived with Ben and Lisa for a whole year, leaving hunting behind. While some hoped (for Dean's sake) that his story could end here, it wasn't in the cards.

While Lisa says Dean isn't the boy's father, he not only looks like the older Winchester but acts like him too (they even have the same music taste). In "Let It Bleed", a demon possessing Lisa "reveals" that Dean is Ben's father, but this line is mostly chalked up to "demon lies" (which, fair). Afterward, Dean leaves his foster family for good.

Amy Pond's son's revenge on Dean (Season 7)

In the episode "The Girl Next Door", we learn that as a kid Sam made friends with a harmless Kitsune who refused to kill. This kindly monster, Amy Pond (Jewel Staite), would later have a child of her own, one she needed to kill for so he could survive. Against Sam's wishes, Dean kills Amy, only for her young son, Jacob (Lyova Beckwitt), to find him above her body.

This traumatic event ends with Dean telling Jacob to "be good", to which Jacob replies that he'll hunt Dean one day. Jacob would have been a great addition for a "monster-of-the-week" episode later on, or even as Dean's final nemesis in "Carry On", but the writers either forgot about Jacob or he moved on with his life.

Closing the Gates of Hell (Season 8)

The whole point of Season 8 was that Sam and Dean would finally slam the Gates of Hell shut forever. With every demon down under, the world would be a much safer place. Sam completed the first two trials: killing a Hellhound ("Trial and Error") and saving a soul from Hell ("Taxi Driver"), but the final trial, "curing" a demon, was interrupted by Dean ("Sacrifice").

This act saves Sam's life but it puts the world more at risk. Dean justifies his actions by saying that they have enough knowledge to turn the tide, but it's all talk. Sure, Sam later cures demon Dean ("Soul Survivor"), but that's it. They never rescue another innocent soul from Hell and the Hellhound-seeing glasses are only seen once more. The tide never changes.

Supernatural: Bloodlines (Season 9)

Supernatural's first attempt at a spin-off occurred in "Bloodlines", which introduced us to the Chicago-based ensemble, including CPD officer Ennis Ross (Lucien Laviscount), shapeshifter David Lassiter (Nathaniel Buzolic), and werewolf Violet Duval (Melissa Roxburgh). The episode revealed a mafia-esque monster conspiracy that secretly runs the Windy City.

Supernatural: Bloodlines didn't take off though, which is a shame since Sam and Dean never return to Chicago again, leaving the ultimate fates of Ennis, David, Violet, and the cast unknown. But more than that, the Winchesters learn that five monster families hold a grip over Chicago and they never go back to do anything about it? Spin-off or not, that doesn't add up.

The Styne Family (Season 10)

Speaking of stories that deserve some greater resolution, the Frankensteins completely disappeared after Season 10. While an easy explanation is that Dean, influenced by the Mark of Cain, slaughtered the entire American branch of Stynes after they killed Charlie Bradbury (Felicia Day), it's said earlier that season that the Frankensteins live all over the world.

With tendrils on every continent, it doesn't seem likely that a major monster family would ignore an entire branch of their family tree falling to the ground all at once. Yet, the Stynes never show their face in America again after "The Prisoner," forcing us to wonder why these magic-dabbling semi-zombies never took the bait.

Sam's desire to "save people" over "hunting things" (Season 11)

In Season 11, Sam went back to his roots. "Out of the Darkness, Into the Fire" brought back the Sam who won fans' hearts in the show's early years, who tried his best to save everyone. This season, Sam exorcises more demons than he kills and saves as many infected people from a rabid virus as he can. This was a really welcomed change at the time but it didn't last long.

Unfortunately, this character arc died halfway through the season and Sam doesn't insist on saving the demon-possessed ever again. After all the experiences they've had with demons previously, especially since Sam had been possessed, you'd think the boys would make this a higher priority than simply killing demons.

The Thule Society vs The Judah Initiative (Season 12)

The Thule Society was introduced as a Nazi "secret society of necromancers" whose nemesis, the Judah Initiative, was a group of Jewish men who fought them since the Second World War. In Season 12, they return with a resurrected Hitler (Gil Darnell) who Dean then kills and brags about for the rest of the series ("The One You've Been Waiting For").

Even though there's a remnant of the Thule out there, they never return. With Hitler gone it almost makes sense, except for the fact that Hitler's death never stopped them before. Also, the Judah Initiative, Aaron Bass (Adam Rose) and his Golem (John DeSantis), are still hunting the Thule solo, so it's odd that we never hear from either group again.

Freeing the Shedim (Season 13)

When Colonel Sanders knockoff Asmodeus (Jefferey Vincent Parise) showed up, he wasn't taken very seriously, but he did have one truly evil plan: releasing the Shedim. These were Hell's most savage creatures, so evil that God locked them away deep. After some bad info from the demon, Jack almost releases these creatures into the world ("The Rising Son").

All we see of these things is a scary-looking arm from the ground, but we know that they mean business. In the final season, Chuck (Rob Benedict) opens every locked door in Hell, which seems like it would include the Shedim, but they don't show. Maybe Chuck decided they were too evil to be let out, but regardless, it seems like a huge oversight.

Grace-enhanced monsters (Season 14)

After the Alternate Michael from Apocalypse World goes back on his deal with Dean, he takes control over the older Winchester's body in order to roam the earth. To wipe out the world's hunters, he mixes angelic grace with monster DNA to create grace-enhanced monsters. One of these turns out to be Garth (DJ Qualls), the friendly werewolf hunter ("The Spear").

Grace-enhanced monsters are mentioned again the following season when Garth's youngest children are born with enhanced abilities ("The Heroes' Journey"). However, the Winchesters never go up against any grace-enhanced monsters again, even though there are plenty still out there who retained their new power.

Eileen Leahy - Sam's final love (Season 15)

Eileen Leahy (Shoshannah Stern) first showed up in Season 11's "Into The Mystic", only to be killed a year later ("There's Something About Mary"). But, Sam managed to turn her ghost into flesh, bringing her back to life ("Golden Time"). The two of them developed a romance that culminated in Season 15. That is until Chuck wiped everyone from existence ("Despair").

When Jack took Chuck's powers, he restored Eileen and everyone else, but when last we see Sam in "Carry On", it seems that he eventually gained a family of his own. While many have speculated that Sam's wife is Eileen, many more fans are upset at the character's lack of clear resolution. We may never know if Sam and Eileen finally settled down, but she's still out there!

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