Stefan Salvatore and Caroline Forbes are trying to resuscitate Bonnie Bennett after she collapsed due to her sudden resurgence of magic. While they panic, Bonnie’s spirit ascends to an astral plane of limbo in the woods. There she sees Elena Gilbert sleeping on a white bed and as she approaches, she wakes up and the two happily reconcile with a hug, Bonnie happy as she thought they would never see each other again. Elena realizes that Bonnie is still young and her joy turns to lament as it dawns that Bonnie has died young and has not yet lived the long happy life she planned on living. Bonnie insists it’s okay and she’s ready to die and can be with Enzo now, but Enzo appears behind Bonnie and tells her he is not and it is not her time and pulls her back to the land of the living where Bonnie wakes up before Stefan and Caroline, happy she is alive and reveals she saw Elena.
Elsewhere, Vicki Donovan rings the Maxwell Bell once before Damon Salvatore attacks and throws her out of the window, much to Matt Donovan’s dismay. Vicki returns to life almost instantaneously and attempts to ring the bell again only for Damon to snap her neck to test a theory. Vicki returns again and Damon realizes she cannot be killed and tells Matt to convince her to let go of her mission and leaves. Vicki tells Matt she cannot do the emotional reunion thing and that Katherine Pierce promised her that she will be free of hell forever if she rings the bell once every five minutes and Mystic Falls has burned and that she will not stop as she cannot go back to hell as it is unbearable torture. She rings the bell again after telling Matt that she would much rather prefer to just be dead and gone than return to hell. Seeing no other way, Matt calls as sheriff to activate an evacuation protocol for a “gas leak” to get everyone out of town.
Damon and Stefan rush into the Salvatore Mansion to get Elena and leave only to find her casket empty. Stefan tells Damon that Bonnie’s heart had stopped earlier and that she said she saw Elena. Elena walks into the room and demands to know if Bonnie is okay and Damon says they are both okay and Elena is increasingly happy that she’s awake and she and Damon hug as Stefan watches on. Suddenly, Damon realizes that she is not Elena and pushes her away instantly as she is revealed as Katherine Pierce, who scolds Damon as “rude” before greeting them “hello brothers”.
Katherine pours herself a drink and tells them that she will not tell them where Elena is and subsequently reveals that she is responsible for the Devil’s interest in the brothers as she had “him wrapped around my finger since the minute I stepped into Hell. Why did you think he wanted you? Because I wanted you, duh.” Damon throws the drink out of her hand and demands to know where Elena is and Katherine simply tells him that it is the perfect revenge and that at 10 pm; Mystic Falls will burn along with Elena and her guess is one of the brothers will die with her. Stefan stabs Katherine with the blade they had made by the Maxwells and she dies and they race against time to find Elena.
Matt reveals to his father that they are running out of time until the recently resurrected Vicki will destroy Mystic Falls.
At the Forbes Residence, Stefan calls Caroline to let her know that he’s been looking for Elena and will now search the high school and she tells him she will meet him there as Alaric Saltzman enters the room, frantically packing for their escape from Mystic Falls. Alaric doesn’t want Caroline to go to the school or stay in Mystic Falls as he doesn’t want his girls to experience what she did when she lost her own mother and Caroline promises that she will put their twin children, Lizzy and Josie, first and get out of the town safely.
Stefan meanwhile finds Elena still in her sleeping coma at the boiler-room of the school, only to be find out Elena has been sealed magically in the room, unable to leave. Stefan calls Damon to inform him of this: he can leave and enter as he pleases but Elena has been sealed in the room. Damon promises to get Katherine to break the spell before she appears behind him, telling him that the bone dagger Stefan earlier stabbed her with is capable of sending her to hell, but she does not stay there and can simply leave unlike Cade. She also reveals that there is no way to get Elena out of the boiler room as Kai Parker had already placed the boundary spell on the room due to their bet and is now permanently indisposed. Damon is tired of the bantering they have done for the past 150+ years and tells her to get to their negotiating already, but Katherine already has what she wants: the town will burn down in Hellfire one way or another and Elena with it. Damon tells her that petty doesn’t look good on her, but she returns that she’s not being petty she’s just gloating. Damon thinks that Katherine is jealous because she knows Stefan and he would choose Elena over her every time, but this doesn’t faze her as she knows Elena would choose Stefan because Katherine would as well as any other woman simply because Stefan is “the better man”, prompting Damon to stab her again.
Elsewhere, as Bonnie, Alaric, Josie and Lizzy drive out of Mystic Falls, Caroline and Stefan call them at the school where they reveal that if Elena will burn in the town, Damon would rather die with her, shocking everyone as they realize Damon might die too. Alaric breaks the silence, telling Caroline to take the underground tunnels and leave town immediately, she hangs up. Stefan tells Caroline he has to talk to Damon and though he knows he will not leave Elena, he has to try. Caroline also tells Stefan she made a promise to Ric to put the girls first and she would help him with Damon otherwise but doesn’t want to leave Stefan, but Stefan convinces her that family comes first: she has to be there for her kids and he needs to save Damon without her as a distraction and they tearfully kiss and separate after professing their love.
At the Armory, Alaric and Bonnie have safely arrived with the siphon twins. Alaric is conflicted as he loves Elena and even cares for Damon but can’t abandon his daughters as they need him and Caroline both. Bonnie reassures him that if they could do something they would do it before seeing a project he and Dorian were planning to destroy hell but couldn’t find a potent enough energy source, but Bonnie immediately realizes that the power they need is inside hellfire and she promptly calls and tells Stefan she knows she’s been hard on him, but “I also know that you and I are equally willing to do anything to fix it” and he agrees. Bonnie tells him she has a plan, but the only way it will work is if Katherine’s in hell when Bonnie destroys it.
Elsewhere, Matt continues to safely evacuate civilians.
Back at the Armory, Bonnie thanks Lizzie and Josie for their parts in saving and making her realize she had all the magic she’d ever needed already inside her. She then asks then for a little luck and each of them stroke her cheeks before Caroline enters, having made it out Mystic Falls only to be told she and the girls and Ric need to leave quickly. Bonnie tells Caroline to leave with Ric and the girls as she (Bonnie) plans to “save the world” and that Ric will fill her in. They hug and Bonnie tells Caroline she loves her. Worried and confused, Caroline tells Bonnie not to do anything stupid and Bonnie confidently tells her she will be fine.
Damon enters the tomb where Katherine’s body burned only to be followed in by Katherine, who tells him she has not missed the place. Damon informs her he predicted that she would show up again and she answers that she isn’t about to miss the “the Elena Gilbert Show”. Katherine wonders why Damon isn’t by her side waiting to die with her as the hellfire will be upon them any moment now. Damon is surprised she doesn’t know considering she’s the Devil now and tells her that Bonnie has found a way to save the day, to which Katherine replies “Bonnie isn’t strong enough to save a kitten”, but Damon knows she’s done it once or twice and will do it again. Katherine adds that this is not a trivial matter and they are talking of “hellfire, so intense it could obliterate anything within miles. What the hell is Bonnie gonna do? She’s thirty minutes away.” But Damon reveals that the tunnels under the town make it a much shorter distance and that Bonnie can draw hellfire through the tunnels away from the town and even better, he believes she can take them both straight back to hell and promptly destroy it with them inside. Katherine calls his bluff, but Stefan walks into the room and tells her that he isn’t bluffing and neither is he as he wants to play the martyr instead of Damon. Katherine decides to let the brothers figure it out amongst themselves and tries to leave the tomb only to be stabbed in the back – literally – by Damon. Once she is dead, Damon and Stefan argue about which brother will stay and make sure Katherine is dead when Bonnie destroys hell with its own power. Damon wants Stefan to go and live and tell Elena he did it on her behalf to pay for his past sins as he’s spilled more blood than Stefan. Stefan, though believes that he owes it to Bonnie and Enzo and a lot more people as he realizes that he’s accountable for his actions whether or not his emotions were off. He is human and in sixty years he’s going to be old and dead while Damon has an eternity with Damon. Stefan doesn’t want to die, he admits, as he and Caroline are now married and he loves her but in the near-two centuries they’ve been vampires, Stefan has fought to make Damon the man who deserves the happiness that is extant with Elena and humanity out there and he pleads, tearfully, for Damon to let him die, if not for Damon, then for himself. Damon tells Stefan he loves him and Stefan returns it, before Damon compels him to leave the tunnels and keep walking out until his death nullifies the compulsion, begging him to be the big brother.
Elsewhere, Peter Maxwell and Matt go to see Vicki one last time as she is about to ring the bell for the last time. Vicki is at first emotionally surprised to see her father, but realizes it must be a trick to get her to stop but that Peter is fifteen years too late to be a father. Vicki tells not going to stop ringing the bell, but they assure her they are not here to stop her and that they actually need her to ring it, prompting Vicki to wonder what they are doing there, to which Peter says he wants to see her a final time. The Maxwells all break down in tears as father and daughter reunite and hug.
In the car Caroline and Alaric are taking out of town, Alaric tells her what Stefan is planning to do and Caroline sobs with despair.
Back at the Armory, Bonnie implores her grandmother to hear her as now would be the best time for her support. She begins a spell, affirming her restored magical powers as Vicki watches her brother and father for what she believes is the last time atop the bell tower as they watch from below, anticipating the hellfire that she prepares to unleash. The room Bonnie is in begins to shake with the build up of Bonnie’s magic powers. Bonnie confidently accepts her powers and continues to chant while elsewhere, Caroline tearfully calls Stefan, only to reach his voicemail, telling him she understands and loves and will love him forever.
As 10˚clock strikes, Vicki rings the bell for the last time, finally unleashing hellfire which kills and seemingly instantly destroys her soul and it bursts through every opening. Before it can reach beyond the threshold of the building, Bonnie magically holds the flames back all the way from the Armory, hindering them from going through to the town. She easily changes their trajectory and steers the hellfire to pulse down to the tunnels below the town, forcing the bell to shoot the flames down instead of outward.
Katherine wakes in the tunnels to see the hellfire pass by her and Damon as he says “poof”.
Stefan’s compulsion wears off as Damon seemingly dies and he rushes back to the town.
In the Armory, Bonnie continues to draw the flames toward the archive (where she is) where the hellfire forcefully explodes through, almost destroying everything in its path, but Bonnie's spell holds back the heat and flames with sheer force of her powers. This act alone far exceeds what her ancestral coven – consisting of a hundred witches – were capable of doing, much less everything she did before while simultaneously planning to use the event to destroy hell, but the force of the hellfire continues to threaten her fighting to claim her and keep hell alive too as her nose bleeds due to the excessive use of her powerful magic. Bonnie – still fighting hellfire – declares, “No! I can do this. I can do this! I can beat you! You can’t have me! It’s not my time!” as she yells this, her mind reaches out to her limbo dimension and Enzo again, who appears and sarcastically notes that now of all times she is ready to live, but urges her to keep fighting to do so. Bonnie finally relents that she thinks it may be too strong for her and that she may not be able to destroy hell after all as more blood drips from her nose. She laments that she cannot do it alone as the fire grows only stronger, threatening to finally destroy her and the Armory and everything after that as she has pulled it away from Mystic Falls. Enzo, though, tells Bonnie she is powerful enough to do anything she puts her mind to and is not alone. In this moment, Bonnie’s hand is taken by Sheila Bennett, who smiles at her, wordlessly encouraging her to not give up. Tearfully, Bonnie continues to chant, with newfound strength she and Sheila continue the spell as Beatrice Bennett’s spirit appears on the other side of Bonnie, replacing Enzo. She too, takes Bonnie’s hand, chanting the spell and urging Bonnie onward to see it to completion. The three of them continue the spell the 100 Bennett Witches started years ago, holding back the flames and in that moment every single Bennett Witch by blood who has found peace appear behind and around Bonnie, all chanting the same spell, willing Bonnie to accept her great potential and to destroy hell itself – among them Lucy Bennett, The Witch of The Five, and Ayana Bennett are all seen. Their combined might and encouragement at last manages to repel the psychic flames back to their own dimension as Matt and Peter watch on back in Mystic Falls, finally destroying hell once and for all. Back at the Armory, Bonnie opens her eyes having stopped hell from claiming her and her friends with the support of her direct ancestors at peace. She gladly asserts, “I did it” with a smile and subsequently passes out.
Back at the high school, Elena wakes up and walks around, seeing and remembering images and periods of her time as a teenager and smiles before bumping into Stefan as she did the the day they met. They greet each other with a smile and “hi”s before Elena wonders what happened to everyone and how she is here right now. Stefan tells her he is now human and that Damon was willing to risk everything for her and the town and that he compelled Stefan to leave, but should’ve known better as Stefan was on vervain and in a flashback, we learn that Stefan had not been compelled but quickly extracted the Cure from his blood before rushing back to the tunnels before Bonnie sent the flames back their way. There, Damon held Katherine patiently awaiting the hellfire to return and engulf them both. Stefan hurriedly injected him the Cure and took over his duty, pushing him into safety while he himself grabbed Katherine and held her firmly in the path of the ensuing hellfire. Katherine begs Stefan to let her go before he tells her to burn in hell, stabbing her with the bone dagger that sends her to hell before Bonnie finally builds up the strength to send it back. When it finally returns, Katherine and Stefan burn and die together before he tells her to “burn in hell” and bids Damon “goodbye brother”.
Back in the present, Stefan reveals to Elena that he is actually dead and she has not yet woken up and they are back in the Limbo Bonnie had earlier visited. Stefan tells her he saw a side of Damon he hadn’t in a long time: an older brother he looked up to, “the son who enlisted in the civil war to please his father . . . the Damon I knew when I was a boy. I wanted that Damon to live and I wanted you to have an opportunity to get to know him.” As they both tear up, Stefan further adds Katherine’s earlier words but applies them to Damon, “he’s the better man. He’s the right man.” He strokes a tear from Elena’s cheek with a smile, telling her it is good to see her again in the place they met one last time and they hug. He then whispers something indistinctive in her ear before subsequently finding peace when walking out of the school doors and into the “light”, only to be met by Lexi Branson who is leaning on his red car which he had previously destroyed in the real world. She retorts that his moment with Elena was beautiful and Stefan replies with a smile, “I was feeling epic”, words Lexi herself had once said to him. She smiles and the they hug with laughter and joy, glad they both found peace together.
Not too long after, Bonnie – having realized she can do anything with her restored powers after destroying Hell and her encounter with her passed family members – simply undoes Kai Parker’s spell on a sleeping Elena as Elena’s voice over says: “Dear diary, today will be different. Today I will smile, it will be genuine. Because today is the day that I get to live again.” When she awakens, she wonders how Bonnie did it and they happily reunite with Bonnie telling her, “It took some time... but I think I’ve finally figured this witch thing out.” with a happy laugh as they laugh only to subsequently realize Stefan really is dead when Bonnie tells her that Damon is with Caroline saying goodbye. Elena continues her voice over: “[...] this life will be good and beautiful, but not without heartbreak. In death comes peace, but pain is the cost of living like love, its how we know we’re alive [...]” as Caroline and Damon are seen in the Salvatore Crypt paying their respects to Stefan’s tomb which reads:
Now at Peace
Damon asks Caroline if she thinks peace exists and she affirms she does and that they will see him again. Damon, though, is jokingly convinced only Caroline will as they will probably reopen up hell for him. Caroline tells him not to be so sure and they hug. They step out of the crypt are happily shocked to see Bonnie with a recently resurrected Elena. Damon and Elena kiss and reunite. Afterwards, Elena tells Caroline what Stefan whispered to her: that he got her earlier message and she is happy. They all then hold a funeral for Stefan and Damon, now human, leaves him his daylight ring and Caroline leaves a Mystic Falls crystal ball keychain and they all leave as Elena’s voiceover says: “and life goes on.”
In the not too distant future, in a series of epilogue montages Matt Donovan's revealed to have continued his journal in a voiceover: “Dear diary, we survived that night, Mystic Falls is safe. I remain the sheriff, they even gave me a bench. I’m thinking of running for mayor. And Vicki, well I think she found peace. Somehow it feels like she did.” And the townspeople are seen applauding Matt for his role as he officializes his bench while Vicki and Tyler Lockwood look on with a smile in the Afterlife and then find peace together.
In Bonnie Bennett’s epilogue, she is seen packing as her voiceover goes as follows, “I'm determined to keep my promise to Enzo. I’m gonna live this life to fullest. I wanna see the world – enjoy my life.” She then wonders if she has packed everything and Enzo's spirit appears (unseen to her) and says she forgot her passport and Bonnie seemingly remembers and goes to get it in a drawer and finds it with the pendant containing Enzo's blood. She then smiles as Enzo's spirit touches her sentimentally, seemingly feeling his presence, but it is made evident she cannot really see him as she continues to pack.
Alaric’s epilogue depicts him opening his school at the Salvatore Boarding House after Damon gives it to them, feeling it is Stefan’s last wish. They name it:
"Salvatore Boarding School for the Young and Gifted"
As they prepare to open the school, his voice over is heard saying: “As for my family, Caroline and I got what Damon decided was Stefan’s last wish.” While his children play in the front yard and rush into his arms, Josette Laughlin is seen watching on with a smile, happy her family still lives on. When Ric feels as though he is being watched, she promptly disappears and he continues to play with his children.
In Caroline’s epilogue (not too long after or possibly the same time as Alaric's), she comments on the state of beginning this new chapter in her life, “Opening the school was hard work, we needed lots of help. Fortunately, we knew plenty of people with experience,”Dorian Williams and Jeremy Gilbert are seen as members of the faculty of the new boarding school and Alaric continues on her line, “Caroline was determined to make it a success, she wanted to make her mom proud” as Caroline drops some letters sent to her from donors to her school and in that moment, Liz Forbes touches her arm and Caroline feels her presence as her mother smiles to her and fades away before she can see her. Caroline then sits down and opens one of her letters as Alaric’s voiceover progresses, “[...] plus, soon after the school opened, she got a most impressive donor, but that is the beginning of another story.” The letter reads:
I have often imagined the paths your life might take, but your chosen future is more noble than I ever fathomed. Please accept this contribution to your virtuous cause. I do look forward to thanking you in person, someday . . . however long it takes.
"After medschool I came home to Mystic Falls. It felt right. It’s where I wanted to grow old and I did. And that’s my life. Weird, messy, complicated, sad, wonderful, amazing and above all – epic. And I owe it all to Stefan. When I met him, I had lost my parents. I was dead inside. But he brought me back to life. And I’m going to live it as best as I can for as long as I can."
A crow flies over her head and she ducks and smiles, feeling a sense of déjà vu and Damon subsequently approaches her. They smile at one another and walk away together, a ring shown on Elena's finger that suggests they married.
In the final epilogue and flashforward, as she and he walk down a Mystic Falls driveway hand-in-hand, Elena reveals that even after a long and happy life together, Damon was still worried that he would never see Stefan again and never find peace, but Elena always believed peace existed in everything we hold dear. Damon then disappears from her grim as they are revealed to actually be in the afterlife, having died of old age together. She then faces her old home and is shocked to find she has found peace as she sees her family on its porch: her mother and father Miranda and Grayson Gilbert, additionally Jenna Sommers and John Gilbert are also seen and come together in tearful hugs and joy.
"That is the promise of peace, that one, day after a long life, we find each other again."
Still in heaven (and in the final scene ever) Stefan is seen in the Salvatore Boarding House drinking what is naturally assumed to be bourbon when he goes to open the front door and finds Damon waiting for him. Damon greets him with the first line said to him in the show’s premiere “hello brother” and they hug, the two brothers, after a long life, having finally found peace together.
All main characters of the show (throughout the eight seasons of the series; except Klaus) were featured. However, as of Klaus, there's a letter featured from him in the last minutes when Caroline's epilogue is shown.
Katherine reveals to Damon that from the moment she entered Hell, she had Cade under her control and this was the reason he was interested in Damon and Stefan, because of her.
Katherine has more screen time than Elena does in the final episode while the awakened Elena appears in about the last 10 minutes.
Kai's sleeping spell on Elena also took into account non-magical means to wake up Elena. Bonnie dying briefly and then being revived wouldn't be enough to wake her, Bonnie would have to stay dead in order for Elena to wake up.
The bone dagger does send Katherine back to Hell, but she doesn't stay there.
Stefan injects Damon with his Cure filled blood making him human. This means anyone Damon ever compelled who's still alive will remember anything they were compelled to do or forget by him, including the wedding guests to Stefan and Caroline's wedding in the previous episode.
Caroline is the last vampire remaining in the series and of this season which started out with 4 vampires (Stefan, Damon, Caroline and Enzo). While the series started out with just two: Damon and Stefan.
This is the 7th episode this season and 49th episode of the series overall to feature all main characters from previous seasons.
The original cut was about 18 minutes longer. One of the scenes cut was Damon's proposal to Elena after the med school. 
Elena wakes up thanks to Bonnie, who didn't die to do so.
Bonnie does what Enzo asked her to do and that was to live her life. She does so by traveling around the world.
Implied but unseen Elena and Damon marry in this episode, in her diary entry there is no mention of any children or grandchildren on their part.
The Salvatore house is turned into the Salvatore Boarding School by Alaric and Caroline. Both Jeremy and Dorian teach there.
Matt remains Sheriff of Mystic Falls, the town gives him a bench and he considers running for Mayor.
Elena seems to be writing a diary entry after med school in the graveyard (where she wrote the diary in Pilot). She also expresses thanks to Stefan for meeting him and what he has done to her. She writes "I wanted to grow old and I did" , and based on the context in her letter, that means she prefers to live and age in Mystic Falls than other places.
Elena and Damon found peace in the end. This can be indicated by the context in her letter "Even after our long happy life together...." "That's the promise of peace, that one day, after a long life, we find each other again".
Katherine's fate is unknown after the destruction of hell, but it's possible that she moved on, being the only realm of afterlife left; however, it is just as likely that her spirit was destroyed along with hell as she was its current ruler, and as such, was tied to the realm like Arcadius before her.
The original ending the writers had in plans was for Stefan and Damon to both die in the name of Elena, who would live on, becoming a doctor and possibly marrying Matt, while being watched by the Salvatore brothers' ghosts. However, Nina Dobrev's exit at the end of Season Six changed things, and prevented the writers from revisiting the love triangle idea.