While Cordelia went to Cancun, Xander, Willow and Oz learned to control the vampire population without the slayer, Giles follows falls trails all over the States, but the new school year starts without expelled Buffy. Under her middle name Anne, she became a waitress in L.A., still dreaming of eternal love with Angel but is recognized by another Sunnydale exilee, whose present alias is Lilly, and helps her search for her sweetheart Rickie, whose life-drained body she finds. Only painfully later they realize that Ken is the culprit, when he pushes them trough a portal to a hell of hard labor- can a slayer handle the taskmaster demons?

Buffy is back home, to her mother Joyce's great relief, which calls for a dinner invitation for the while gang, but the mood remains gloomy, despite her resuming the main slaying tasks although for the others things can't just return to their former state, not in the least because the obviously amused principal Snyder pays no attention to pleas to take Buffy back (mother's threat to take the case to the mayor even has an inverse effect), while Buffy still dreams of Angel. After a dead cat found in the Summers bookcase, other stinking corpses come to life again, a phenomenon which must have something to do with a the mysterious Nigerian mask with lighting red eyes mother Joyce bought, fortunately no secret to Giles...

The gang enjoys being Seniors now. The Summers girls gloat the school board overruled the principal's refusal to allow Buffy back after make-up tests, but guilty nightmares about having slain her beloved Angel still plague Buffy, who remains too gloomy to accept a charming dance invitation from cute student Scott Hope, but he sweetly persists his charm offensive. Following a suspected vampire, Buffy finds the presumed victim is the new second slayer, Faith, who considers Giles hunky for a watcher. A limousine arrives in Sunnydale with upper-class vampires: the gravely mutilated Kakistos and his lieutenant, Mr. Trick. When some underlings attack the slayers in Kakistos's name, Giles warns it's Greek for 'the worst'... Buffy admits Willow's spell had cured Angel just before she slew him; somehow he reemerges from the hell-dimension her slaying sent him to.

Xander minds Oz, caged in the library for his lunar werewolf nights, but dozes off; a boy is kill in the woods and the window is open, so Faith takes second watch. Buffy dates gentle Scott Hope and takes mandatory school counseling with Mr. Platt, who says she must conquer her 'demon', obsession with a lost love. Looking for the werewolf, Buffy bumps into Angel, now a half-naked beast, and locks him up cuffed to chains in the mausoleum but tells nobody, not even Giles who says even after centuries of torture in the hell-dimension he may still be a redeemable monster, then finds Platt, murdered during the day. Scotty's school friends Pete Clarner and Debbie Foley share a horrible secret. The gangs suspects them because of links to the victims, meanwhile Angel breaks his chain...

Buffy and Cordelia battle against one another for Homecoming Queen. Meanwhile, Mr. Trick puts together a group of hunters to track down Buffy and Faith in "Slayerfest '98."

As Buffy deals with Giles and her mom treating her too much like a child, the mayor hires Ethan Rayne to make special kinds of candy bars. The more candy the adults of Sunnydale eat, the more they begin to act like teenagers.

Gwendolyn Post, an uptight, by-the-book English Watcher, arrives in Sunnydale claiming that the Watchers Council sent her as Faith's new one, or rather to assess the whole situation in Sunndydale, looking down upon understandably stressed Giles as on his library. She takes charge of their next, common mission: slaying the demon Lagos and destroying his weapon, the glove of Myhnegon, which is in the tomb of the von Hauptman family on Restfield cemetery. Meanwhile, Angel, back to his tender self, gets it for Buffy, but is seen kissing her by Xander, who reports this to Giles, who is deeply hurt, especially with Miss Post breathing down his neck, but doesn't tell her. With all of her friends angry and upset that Buffy didn't tell them that Angel had returned from Hell, Xander, worried and (despite kissing Willow again) again maliciously goes behind Buffy's back and informs Faith about Angel's return and persuades her to kill him before he may turn evil again. When Giles shows the surprised Gwendolyn the glove Buffy brought him and the rit all he found to destroy it, her hidden agenda proves a huge problem for everyone, the gang only finds out when Faith is already on the wrong foot...

The gang plans to celebrate their SAT scores bowling, Buffy's mother's insistence to go to a decent college is promoted by Giles and Angel. Willow has a worse regret then her relative failure, rekindling passion with Xander; determined to save their relationships with Oz and Cordelia, she visits a magic shop for the necessary ingredients for a reverse love potion. Xander finds her and objects to another inexperienced witch messing with him. They are actually stopped and captured by Spike, who has returned, observed Angel, followed Willow and now forces her to make a love potion to return Drusilla to him. Before Buffy and Angel have got hold of Spike and made him tell they're in the abandoned factory, the crypto-couple is found, kissing fearing their last hours, by Oz and Cordy, who thus get hurt in more then one way...

Wanting to be rid of Xander for good, Cordelia comes to the conclusion that Buffy is the cause of all her problems and makes a wish to the new transfer student, Anya, that Buffy had never come to Sunnydale. Anya, being the evil and powerful vengeance demon Anyanka, grants that that wish and in a heartbeat... the entire world changes... and everything Cordelia knows is completely different. In this alternate reality of 'It's a Wonderful Life gone to Hell': the Master is alive and rules the town after dark from the Bronze; both Xander and Willow are vampires; and Giles with a small group of brave students, called The White Hats, are fighting a losing war of attrition against the vampires on their own. Then in a shocking turn, Cordelia gets killed by the vamps, leaving the alternate reality Giles to figure out on his own what has happened to this world they currently live in, leading to a meeting with the alternate reality Buffy.

People in Sunnydale prepare for Christmas tide, except Jewish Wilow, who tells lover Oz she's ready for physical intimacy, he decides to wait. Now his physical suffering is over, Angel is haunted by a new kind of nightmares and visions, always and everywhere, about Angelus' horrible past since the 19th century, with victims and other persona appearing and talking to him. Learning those visions even enter Buffy's dreams, focusing on sex with her to lose his soul and then killing her, Giles agrees to do research as Angel desperately begged him; he is helped by Buffy and Xander, for whom Christmas is a nightmare of lacking any family celebration. They find that Angel is tormented by the Bringers or Harbingers of Death, the three high-priests of the First Evil, older then demons and incorporeal, and Buffy finds the mark of its residence. Angel can't stand the fear of giving in to temptation at the price of her life and resolves to commit suicide by sunrise, Buffy's pleading to make him resist seems to fail, only a Christmas miracle can save the seasonal day...

The discovery in Sunnydale park of a boy and girl aged 7-8, apparently murdered ritually as indicated by markings, soon tracked to witchcraft -as used by sorcery apprentice Willow-, has an unusual emotional effect. Buffy's mother, who was there in an attempt to bond, founds the soon influential Mothers Opposing the Occult, MOO, actually including fathers and sympathizers, which alas targets white as well as black magic, even slaying, actually urged by the two killed kids to 'hurt the bad girls'. Eagerly helped by principal Snyder, mayor Wilkins and the police, MOO manages to have the school lockers searched, Giles' books confiscated and risking to end up a stake, where they believe witches must be solved, even if this extreme 'punishment' concerns their own daughters. When the gang realize nobody ever identified the kids, they find there's more to Hans and Greta Strauss, in their dark past...

For her upcoming 18th birthday, Buffy declines the Scooby gang's offer of a big party, hoping to celebrate with quiet reflection and a traditional trip to the ice show with her father. But Buffy doesn't know that preparations are being made for a life-threatening rite of passage that drains the slayer of her powers and then entraps her with a powerful and psychotic vampire foe.

When Xander realizes that he isn't needed as much as he'd like to believe, his quest to prove he's cool leads him to an unforgettable night that finds him consorting with fast women, raising the dead and rolling with a dangerous crowd that could put Sunnydale in a world of hurt. Meanwhile, Buffy, Giles and the rest of the crew engage in a furious battle with the Sisterhood of Jhe, an all-female demon apocalypse cult that intends to reopen the Hellmouth and bring about the end of the world.

The gifted students enjoy early college admissions, while Xander and Buffy rather worry about present high-school exams. The mayor and his cronies look forward to his demonic ascension, after 100 days of invulnerability. Buffy's council-appointed new, young Watcher Wesley Wyndam-Pryce is received coldly, forbids Giles even to be kept informed but proves his research-excellence by identifying instantly swords as belonging to the 15th century duelist vampires sect El Eliminati, the survivors of which still look for demon Balthazar's buried amulet; Buffy and Faith successfully search for it at the cemetery and clean out a vampire layer. Angel takes the amulet: it's not safe enough with greenhorn Wesley. The order reports to Balthazar's blob-shaped representative about his amulet. Impetuous Faith drags Buffy along, they get arrested and kill the innocent deputy mayor Allan Finch. Both watchers get captured by the sect, Angel brings the slayers...

Buffy tries to convince Faith to face up to the consequences of her actions, but Faith thinks that being a Slayer puts her above the law. Buffy confides in Giles about the accidental murder and he decides not to involve the new Watcher, Wesley, knowing that Faith is extremely unstable. Angel tries to get through to Faith, but when Wesley discovers the truth and comes after her, Faith's trust in Buffy and the gang is destroyed.

Anyanka, the demon who used her power to grant wishes to let Cordelia unwillingly create a world without Buffy as Sunnydale slayer, failed since then to get top-rank demon D'Hoffryn to rehabilitate her, but finally gets a chance to succeed in her menial incarnation as Sunnydale High pupil Anya: Willow, who is frustrated as a girl and individual, always taken for granted, in Buffy's shadow and just got railroaded by principal Snyder to 'tutor', or in fact slavishly do the paper writing on her own, for a spoiled jock brat, hunky Percy West, who even explicitly barks at her as his menial flunky, naively accepts to help 'Anya' with a black magic spell. Willow realizes only too late she's really working for the wrong side, stops before Anyanka's power-amulet is revalidated, but still summons a parallel Willow from a black dimension where she's a master vampire, who now makes her grand entry in Drusilla-style at the Bronze, co-existing with gentle Willow. The gang has no time to mourn 'the best of us', who urgently must join in again with Angel, while the new official Watcher, Wesley Wyndam-Pryce from England, proves of little use, to survive and get rid of the dark 'alien' version, while both go undercover as the other...

As a part of her new alliance with the Mayor, Faith tries to seduce Angel so that he will again lose his soul. When that fails, the Mayor summons a powerful demon to remove Angel's soul with dark magic.

After an encounter with a mouth-less demon, Buffy is infected with the demon's blood and she gains the ability to hear people's thoughts. At first her newfound ability is useful for cheating on schoolwork and eavesdropping on the thoughts of those around her, but when the voices continue to flood her mind, she realizes that she cannot control the power. Amid the chaos, Buffy hears a killer planning a mass murder at the school. Now she must keep herself from going mad long enough to prevent a catastrophe.

Nearly all the gang is admitted to colleges, Willow even Oxford; only Xander plans to tour instead. The mayor gives Faith a precious weapon as reward, and the mission to intercept at the airport the box of Gavrok, a container of mystical energy he needs for his demonic ascension. Mother Joyce hopes Buffy goes to Northwestern University, near an aunt in Illinois, but the watchers doubt if her slayer-duties allow any long absence from the Hellmouth; maybe if she first prevents the ascension, therefore Giles agrees to seize the initiative once they know more, quickly done ignoring Wesley's caution by the Council's book. Angel helps Buffy steal the box from the town hall, but Faith takes Willow hostage, only Wes would refuse to exchange her. First Willow kills a vampire guard and consults the Books of Ascension; at the meeting of both sides, the box is dropped, spilling some of its spider-scary content...

The gang insists the watchers should at least allow them a glorious prom night before fighting the mayor's ascension. Mother Joyce Summer's speech it's up to mature lover Angel to make hard choices her teenage daughter is incapable of gives Angel nightmares about a wedding in an empty church after which Buffy burns in sunlight, so he decides to give her a normal love-life by breaking up, he'll leave Sunnydal after the ascension. Xander finds out spoiled Cordy has to work in a fashion shop now the IRS has taken her dad's last dime, they are attacked by a hell-hound which seems trained to target formal dressers and is electronically brainwashed by Buffy's scorned admirer, chemistry student Tucker Wells. Buffy decides to slay-chaperon the prom for the others, hunts the hell-hounds and gets surprising bonuses...

The gang seeks a cure for Angel, who has been shot by Faith with a poison arrow. Meanwhile they try to find a way to stop the Mayor's Ascension and Buffy has a showdown with Faith.

Buffy forces Angel to drink her own blood to rid his body of Faith's poison. With Buffy in a severely weakened state, the gang decides to rally the masses of Sunnydale High to defeat the Mayor once and for all.