Supernatural’s penultimate episode left a lot of fans scratching their heads in confusion. The episode saw Chuck defeated and left helpless while young Jack absorbed his powers and basically became God. There were echoes of the original planned series finale, the fifth season’s last episode “Swan Song,” as Lucifer and Michael fought each other, and both Sam and Dean took a bloody beating from a higher power. After Jack completed a particularly impressive ascension to a higher plane of existence, he left Sam and Dean in their bunker, drinking to lost friends—“to everyone we’ve lost along the way”—and driving off into the sunset. It was a good series finale. Only one slight problem: this wasn’t the show’s final episode. Everything about this episode felt like a series finale—from Chuck making a fourth-wall-breaking joke about “canceling your show,” to the montage of clips from fifteen years of Supernatural that played over the last few minutes, to the reappearance of fan favorite character Lucifer. Many viewers genuinely questioned whether they’d missed something, whether this was actually the finale after all. But that’s not the case. “Inherit The Earth” is only the penultimate episode of the series, with the finale episode, Carry On, to follow. So what gives? Supernatural is not the first show to wrap up its main story arc an episode before the end of the season. One of the most well-known examples was season four of Buffy The Vampire Slayer, in which the season-long story arc involving government program The Initiative was wrapped up in the penultimate episode of the season. This left the finale free for something much more experimental: a dream episode packed full of foreshadowing for the upcoming fifth season, as well as reflections on how far the characters had come since the show’s beginning. More often, though, it’s the whole series’ story arc, not just a one season arc, that gets wrapped up early. This has happened a few times in sitcoms. The Office season nine, for example, wrapped up its ongoing plot threads in penultimate two-parter “A.A.R.M.,” which saw Darryl leave the office and Dwight finally propose to Angela, before cutting to black on the documentary filmed across the course of the series finally airing. The actual series finale, another two-parter aptly called “Finale,” skipped a year ahead in the timeline and took place at Dwight and Angela’s wedding. By contrast, in New Girl, lead characters Jess and Nick, whose romance had driven much of the show’s plotlines, got married in the penultimate episode, so that the series finale could focus on the series’ five main characters playing one last game of True American as they said goodbye to the loft apartment that had brought them together. In The Good Place, our four formerly human heroes are finally admitted to the titular Good Place two episodes before the end. The penultimate episode deconstructs the problems with the Good Place and offers a solution, as well as putting former demon Michael in charge, while the actual finale follows each character through the millennia to their ultimate fate. In all of these cases, the reason for wrapping up the arc plot early is to allow the finale to focus on character development and on giving the characters an emotional send-off. In the case of The Office, this meant a time skip to show us all the characters, plus a special guest in the returning Steve Carell as Michael Scott, coming together for the wedding and dealing with the repercussions of the documentary’s release. In New Girl’s case, it provided an episode focused on the core five characters – not a wedding which privileges two of them and features multiple guest stars. In the case of The Good Place, it allowed the audience to watch the characters grow, and to see their ultimate fate, even beyond the afterlife. The character growth seen across the episode was a bit under-cut by the whole thing being reversed and only Teal’c retaining any memories of it (as well as decades of aging) at the episode’s conclusion, but it offered a meditative, character-driven final hour in which we got to spend more time just chilling with these characters, rather than a frenetic, action-driven finale. This kind of thing can backfire badly, however, if it’s not what the audience are expecting. The most notorious example of that is probably Star Trek: Enterprise’s series finale, “These Are The Voyages.” Having, once again, wrapped up much of the series’ arc in the previous two-parter, the finale infamously brought in Jonathan Frakes and Marina Sirtis from The Next Generation to show Riker running a holodeck program recreating events around the decommissioning of the Enterprise NX-01, including the very rushed death of one of Enterprise’s main characters, Trip Tucker. You can see why the showrunners thought this would be a good idea, offering a nice tie-in to another branch of the franchise in a crossover with an unusual structure (it’s set entirely within an episode of The Next Generation, season seven’s “Pegasus”). It was a concept they had planned for the season finale before the show was cancelled, which probably would have rankled less with fans (Trip’s death aside) since one of the main complaints about it as a series finale was that it shifted the focus to the Next Generation characters at the expense of giving the Enterprise characters a proper goodbye. If it had been just an experimental season finale, like Buffy’s, this probably would have been less of an issue. In a way, the episode works quite well as a finale to all of what could broadly be called “90s Trek”, the period from 1987-2005 when Star Trek was constantly on the air – Enterprise was the last televised Star Trek to air until Discovery’s debut in 2017. But as a finale to the four-year run of Enterprise, fans found it deeply unsatisfying. There are issues with the episode on the level of plot; for example a nice moment between T’Pol and Tucker only happens as a result of Riker’s interference, meaning the “real” T’Pol and Tucker fans have been following for years probably never experienced that moment. But more importantly, the audience wanted to spend time with the core characters from Enterprise, not with Next Gen characters they’d already said goodbye to eleven years before – Tucker’s sudden death just rubbed salt in the wound. So where might Supernatural be going with this structure? We can probably rest easy that it won’t be giving us a finale quite as unpopular as Enterprise’s. Supernatural hasn’t managed to kick-start a franchise despite a couple of attempts, and it’s probably safe to say the finale will focus on the series’ two leads, Sam and Dean Winchester. In fact, we can see how the writers have been clearing the decks for exactly this reason over the preceding two episodes – killing off third series lead Castiel two episodes in advance (though he may, of course, make an appearance of some kind in the finale) and wrapping up season fifteen’s fourth lead, Jack’s, story in the penultimate episode. This is a show that knows fans have followed the two main characters through thick and thin for a decade and a half, and that they want to spend the final two hours with the Winchesters. But Supernatural has taken this structure further than any of the other examples we’ve looked at. “Inherit The Earth” didn’t just wrap up the arc plot, it also included a finale-style montage and ended with Sam and Dean driving off into the sunset in the Impala – which is literally the ending many fans have been hoping for, for years. Unfortunately for everyone in that camp, this almost certainly means that this isn’t how the show is actually going to finish. And that means that the greatest likelihood is that Sam, Dean, or both of them, are going to die. Again, it’s anyone’s guess how this will play out exactly – the closest we’ll get to trying to predict it, is to say that “Swan Song” killed off Sam and left Dean to go live out his life with his girlfriend Lisa, so we wouldn’t be surprised if “Carry On” kills off Dean and leaves Sam to live out his life with his presumably-resurrected girlfriend Eileen.