Buffy gradually learns to accept her role as the Slayer and prepares to battle the Master's minions in order to stop the Harvest, a ceremony which will free the Master from his prison in the sewers. Willow and Xander are confided in by Giles about the existence of Vampires and Demons and, although overwhelmed, pledge to help Buffy in her fight.
The new principal forces Giles to run Sunnydale High's annual talent show and Buffy, Willow and Xander have to perform against their will. Things get worse as the talent show proves to be a deadly place when one of the participants is found with her heart removed and the clues all point to one boy and his ventriloquist puppet.
When a cool, badass vampire named Spike comes to Sunnydale intent to use the Hellmouth's power to save his lover, Drusilla, he attacks Sunnydale High on Parent-Teacher Night to destroy the Slayer to prove his worth to the Anointed One. With all her friends' and families' lives at stake, Buffy needs to find a way to stop Spike and his vampire gang, while also having to lead her friends and her mom to the path of survival.
While on a visit to the local museum one of the students accidentally breaks an ancient seal buried with an Inca Mummy. Without the seal to hold her, the mummy rises and must consume the life force of the living in order to stay alive. When she consumes the identity of Ampada, an exchange student, Buffy have to stop her from seducing Xander into her death list.
On Halloween, Buffy, Willow and Xander are 'volunteered' by Principal Snyder to take groups of kids trick-or-treating. They get their costumes from a new store run by an Englishman, Ethan Rayne. Xander chooses a soldier outfit, Buffy buys an 18th century noblewomans dress to impress Angel; and Willow, despite Buffy's attempts to get her to dress in a sexy skirt and halter, dresses as a ghost. Unfortunately Ethan turns out to be a bad guy and casts a spell to transform everyone into their costumes, and causing Buffy and Xander to have amnesia. When Spike and his vampire gang attacks them, Willow, Giles, Angel and Cordelia team up to save Buffy and the rest from being dinner, while they also need to put a stop on Ethan's curse spell.
Ford, an old boyfriend of Buffy's comes to Sunnydale and, unknown to her, is part of a secret sect which worships vampires. While the others in the sect are misguided teens who believe that vampires are a higher order of life, Ford has a more sinister reason for his deciet. Because he is going to die soon of cancer, he makes a deal with Spike to hand over Buffy in return for eternal life.
The secrets of Giles' unnatural past as a wild teenager are revealed when an old friend of his comes to warn him that a demon that they both summoned has returned. As a young man, Giles turned in his Watcher studies in favour of dabbling in witchcraft and the occult with his old buddy Ethan Rayne and several others. They discovered Eyghon The Sleepwalker and summoned him while one went into a deep sleep. Unfortunately, Eyghon gained power by this and killed them all one by one over the years by possessing a dead or unconscious person and is now after the last two members, Giles and Ethan.
Its Career Week at Sunnydale High and Buffy is faced with the reality that she has no future apart from that of a Slayer. Meanwhile, in order to stop the Slayer from ending his plan to restore Drusilla's strength, Spike sends four deadly assassins to ensure the Slayer has no future. Also, a mysterious girl is following Buffy and Angel around and Xander and Cordelia are trapped in Buffy's house after being attacked by one of the assassins.
After getting in a fight with the mysterious woman, Kendra, Buffy learns that her temporary death in the hands of the Master had activated the choice for the next Slayer, and she is fighting her. After calling a truce and convinced by Giles to work together, Buffy and Kendra team up to save Angel from Spike and Drusilla. Meanwhile, trapped in Buffy's basement, Xander and Cordelia start their relationship and Willow and her computer-mate, Oz start an intiguing friendship, until Oz is shot by another assassin who targets Buffy.
On Buffy's 17th birthday, Drusilla prepares to awaken a powerful demon named The Judge who was brought forth a thousand years ago to rid the Earth of the plague of humanity. His body was dismembered by an army and the parts were buried in every corner of the Earth but somehow all the parts have made their way to Sunnydale. Buffy intercepts one of his arms and Ms Calendar convinces Angel to take it to the most remote region possible. Unknown to everyone else, Jenny Calendar is actually Janna, a descendant of the Romany clan who cursed Angel and has been sent to Sunnydale to ensure that the curse isn't lifted. Buffy and Angel say their goodbyes at the docks when they are ambushed by Spike's gang who retrieve the arm and Drusilla is able to reassemble the demon. Buffy and Angel just manage to escape from The Judge and while recuperating in Angel's apartment, they consummate their relationship.
Angel is still in the street in pain but suddenly the pain stops and his first act is to kill a human. Angelus has returned as a result of he and Buffy making love. Meanwhile The Judge is returning to full power and Spike is impatient to get on with the killing when Angelus walks in and declares that he is back. The three reunited once again prepare to unleash The Judge on Sunnydale and Angelus persuades them to let him kill Buffy before they begin. Willow discovers Xander and Cordelia kissing and runs from the library only to be met by Angelus. Buffy comes in and fights him off and they ponder what could have happened to turn him evil. Buffy realises that she was the cause and runs off. Angel appears to her in a dream to warn her about Ms Calendar and Buffy confronts Jenny demanding answers. She reveals her heritage and says that the curse can only be lifted if Angel experienced a moment of true human happiness and he is no longer plagued by guilt and remorse.
Xander tries to use Valentines Day to further his relationship with Cordelia but she succumbs to peer pressure and breaks up with him. With the help of Amy (who is exploring her mother's witch powers), he puts a love spell on her which goes horribly wrong, turning him into every woman's desire; except Cordelia's.
As the Sadie Hawkins Dance nears, Buffy faces inner demons as she feels responsible for Angel's epiphany, meanwhile Sunnydale High is even more dangerous than usual as the ghost of a former student who killed his sweetheart and then committed suicide haunts the halls forcing people to relive the moments that killed them over and over.
Angelus' origins from being vamped by Darla in 1753, vamping Drusilla in 1860, being cursed by the Gypsies in 1898, and meeting a demon named Whistler in New York in 1996 who shows him a better way of life are revealed while Angelus prepares to awaken Acathla, an ancient demon that will suck the Earth into the Demon Dimension. Buffy and Willow find the spell to restore Angel's soul and Willow declares that she knows enough about magic to perform it. The gang almost come to blows when Xander tells Buffy outright that she doesn't care what happened to Ms Calendar, she only cares that she can get her boyfriend back. Kendra returns to Sunnydale because a dark power is rising and comes bearing a sword blessed by the knight who first slew Acathla. Angelus tries to awaken the demon but fails. Needing someone to help him with the ritual, he distracts Buffy while Drusilla goes to collect Giles. Drusilla and her friends attack the rest of the gang but only Kendra is there to defend them.
After Drusilla's attack on her friends which resulted in the death of Kendra and Giles' abduction, Buffy is arrested for the murder but escapes from the police. She heads to the hospital where she learns that Xander has a broken arm and Willow is left in a coma. They all realize that Giles was taken by Drusilla and Buffy prepares herself to face Angelus. After being stopped by another cop, Spike comes to her aid and convinces her that he wants to be rid of Angelus too and they form an unusual alliance. Buffy is forced to slay a vampire in front of her mother and tells her the truth but she does not want to accept it. When Buffy tries to leave to fight Angelus, Joyce tells her that if she goes she better not bother coming back. After retrieving Kendra's sword from the library she heads toward Angelus' mansion. Meanwhile, Willow wakes up and decides to try the spell again and Xander runs to Buffy's aid.
Willow, Xander and Oz are attempting to keep the Sunnydale vampire population in check during Buffy's absence with only moderate success. As the gang restarts school we learn that Buffy is working as a waitress in L.A. using the name Anne and trying to forget her old life. Buffy runs into Lily (formerly known as Chanterelle) and her boyfriend Rickie who quickly turns up missing. Buffy discovers Rickie dead but mysteriously aged to an old man. Continuing her investigation Buffy tracks down Ken (a social worker) and Lily and all three fall through a portal in the floor. They are in a demonic factory where the humans are slave labor. Back in Sunnydale the gang succeeds in staking a vampire though it's not exactly pretty. Meanwhile Buffy and Lily wake up in a cell and Ken explains they are in an alternate dimension where a hundred years passes before a day on Earth goes by. Buffy overcomes the guards with some help from Lily and leads her and the other slaves back to Earth.
The new Slayer Faith arrives in town and seems like a fun-loving wacky teenager who integrates herself into the gang. While Buffy is getting 'Single White Female-d' she notices that Faith is becoming more mysterious and discovers that she has been followed by an ancient vampire who murdered her watcher.
Xander finds out about Angel's return to Sunnydale and promptly informs the gang who confront Buffy with the fear that he may turn evil again, while Faith finds herself under the wing of a new Watcher, Gwendolyn Post, an outwardly prim and proper Englishwoman who was expelled from the Watcher's Council for practicing evil magic.
Spike returns to Sunnydale a shadow of his bad-ass vampire self and kidnaps Willow so she can put a love spell on Drusilla. While he is out collecting magic spell ingredients and convincing Buffy why she shouldn't kill him, Willow and Xander lose their inhibitions in the heat of the moment only to be caught in the act by a rescue party in the form of Oz and Cordelia.
While the gang prepares for their Christmas vacation, Angel is haunted by visions of his violent past. A mysterious force called the First Evil takes the form of Jenny Calendar and tries to convince him to lose his soul in Buffy and become evil again. Believing that he isn't strong enough to fight the demon within, Angel waits on the top of a hill for the sun to rise. Buffy finds him and tells him to fight back, that he can do real good in this world, but just as she is giving up it begins to snow, preventing Angel from being killed by the sunlight. Meanwhile, Willow goes to great seductive lengths to win Oz back.
Picking the wrong night for mother-daughter bonding, Joyce discovers the bodies of two children apparently sacrificed in an occult ritual and she rallies the adults of Sunnydale convincing them to rid the town of evil, including Buffy, Willow and Amy. Giles soon realises that the children are actually demons that do not kill people themselves but invoke fear and panic and gain their power by watching normally calm and sane people persecute each other.
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 unbeknownst to Buffy, 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 vampire foe that she must defeat in a defenseless state in order to pass the test.
When Xander realises that he isn't needed by the gang 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. Also, Faith and Xander grow somewhat closer when they have sex after he saves her from an apocalypse demon.
While on a mission to retrieve an amulet before a powerful demon can restore his strength with it, Faith introduces Buffy to her reckless method of slaying which leaves Buffy wanting more of the wild life; while Giles is trying to keep his cool in front of the stuffy new watcher, Wesley Wyndam-Pryce. When Faith accidentally kills the deputy mayor Allan Finch, she tries to clean up the crime but when Buffy confronts her about her actions, she simply replies "I don't care."
Buffy tries to face up to the consequences of her wild actions with Faith but Faith seems to think herself above the law. Buffy confides in Giles about the murder and he oversteps his bounds by not involving the new Watcher, Wesley. Angel captures Faith and tries to connect with her but Wesley and the Watcher's Council intervene and take Faith to be transported to England. Faith escapes and prepares to leave Sunnydale on a cargo ship but Buffy finds her. Mr Trick and several vampires attack them and Faith saves Buffy from almost being bitten by Trick. Buffy and the gang think that Faith can be saved but while they discuss it, she is offering her services to the Mayor.
While unknowingly participating in a spell with the wish-granting demon Anyanka in order for her to get her powers back, Willow accidentally brings forth the vampire Willow from Cordelia's alternate universe. The vampire Willow sets her sights on turning Sunnydale into the vampire-ruled world she knows but when she learns of her counterpart, she decides to make Willow send her back. After trying to seduce Willow and freaking her out a bit, the vampire Willow is captured. The real Willow, dressed in her doppelganger's outfit, attempts to stop the ensuing slaughter at the Bronze and is almost killed by the vampire Willow before Buffy saves her. Giles and Anya successfully send the vampire back to her world but she arrives at the exact same moment she left, right before she is staked by Oz.
Faith's new alliance with the Mayor goes as far as them conspiring to rob Angel of his soul. Faith tries to seduce him but he is thinking Buffy Summers in a big, one-track way. When the old-fashioned way doesn't work, the Mayor summons a powerful sorcerer who does the job for them. Faith and Angelus team up and capture Buffy but while they are preparing to torture her, Faith lets loose some details about the Mayor and his upcoming Ascension; at which point Angelus reveals that his being evil was all an act for them to get information. Faith escapes after she and Buffy battle and Buffy tells Angel that she needs some time alone after having to watch him and Faith kiss.
After a close encounter with a mouthless demon Buffy is infected with the demon's blood and she gains the ability to hear people's thoughts. Her new found ability at first is good for cheating on schoolwork, but when the voices continue to flood her mind, she realises that she cannot control the power. While the gang tries to track down a would-be killer at the school, Buffy is slowly going crazy from the inability to block the noise from the minds of the people around her.
Buffy's acceptance to college leaves her with even more doubts about her life outside of Sunnydale with Faith and the Mayor still around. Buffy decides to take the fight to the Mayor and discovers a secret delivery for him, the Box of Gavrok which contains a mystical energy vital to the Ascension. Buffy and Angel successfully break into Town Hall and snatch the box but unfortunately, Willow is captured by Faith. Are they willing to give up their best chance at avoiding the Ascension to save Willow's life? Is there any doubt?
As the all time night-of-nights for the senior students peeks around the halls, Buffy must save her friends and the rest of the school from a scorned student who has trained a pack of hellhounds to attack formalwear. Meanwhile, Angel reveals his feelings that he and Buffy could never have a normal life together and has decided to do the right thing and break up with her and plans to leave town after the Ascension. Of course Buffy saves the day and her night doesn't turn out so bad when she receives a special Class Protector award from her fellow students and Angel shows up looking very dapper in a tux and asks for one last dance.
The gang receive some valuable information from old enemy Anya who has actually witnessed an Ascension. She reveals that the Mayor plans to transform himself into pure demon, something that has not been seen for thousands of years. When Angel is poisoned by Faith to distract Buffy, Buffy faces Faith for the final time in order to get the only cure to the poison: Faith's blood.
After their ultimate 'Fight-to-the-Death' Faith escapes from Buffy, albeit in a coma, so Buffy offers her own blood to Angel to rid his body of the poison. When she recovers the gang finally devise a plan to defeat the Mayor, rallying the students and asking for their help in fighting the resulting serpent demon before Buffy leads him into the library which has been rigged with explosives.
Buffy moves into her dorm and attempts to adjust to college life. Everything around her seems to have changed without the constant interaction with the gang she had in High School. With Giles becoming a 'gentleman of leisure', Willow getting more and more excited about college and Xander still away on his road trip, she again believes that she must fight and survive on her own when she discovers a gang of tough vampires operating on campus.
Dorm life proves to be a challenge as Buffy has to deal with a roommate who is more than a little bit difficult. Kathy continually imposes her idiosyncrasies onto Buffy and even begins to invade her dreams which has Buffy acting just a little too strange about the situation. Buffy sets her sights on Parker Abrams, the first college guy to pay her any attention, but when Kathy becomes more friendly with him than her, Buffy declares that she must kill Kathy.
Spike returns to Sunnydale with his new girlfriend Harmony who is now also a vampire. Spike is searching for the Gem of Amara - a stone which makes vampires invulnerable, which he believes is buried somewhere under Sunnydale. Buffy is preoccupied with her budding relationship with Parker and sleeps with him but he proceeds to ignore her. Meanwhile Anya returns and throws herself at a flabbergasted Xander.
Angel covertly comes to Sunnydale fearing Buffy is in danger after Doyle's vision of her in Angel. While digging for a new Cultural Centre at the college, Xander falls into a sacred Indian burial area and releases Hus, a vengeance spirit of the Chumash Indians, the original residents of the Sunnydale area. Buffy is busily planning a traditional home cooked Thanksgiving while people around Sunnydale are being killed and Xander gets sicker and sicker. Hus summons a group of warriors and they attack Buffy and the gang at Giles' house. With Angel's help they repel the attackers until Buffy finds a way to kill Hus. As they sit down to dinner Xander lets it slip that Angel was in town.
The entire town of Sunnydale goes silent when a group of fairy tale demons called The Gentlemen appear and steal everyone's voices. Without being vulnerable to the one thing that can kill them (a human scream) they are free to steal the hearts of seven people. Buffy and gang must solve the mystery and overcome the bad guys without being able to discuss anything.
Buffy and Riley have to work out their relationship given their new understanding of what they do. An earthquake rocks Sunnydale and Buffy worries that it could signify the end of the world. They find out about a group of demons who are in town collecting sacred items which together have the power to end the world. When the plans of the demons are uncovered, the gang must return to their former sanctum inside the dilapidated Sunnydale High School (the library) to stop the Hellmouth from opening.
At Buffy's 19th birthday party, Giles finally realises that he is a middle-aged man hanging around with a bunch of teenagers and starts to get depressed about his life. He feels even more like the third wheel when he finds out about Riley and the Initiative, which Buffy neglected to tell him about. When Ethan Rayne returns to town, instead of kicking his butt back to England, Giles goes for a drink with him. The next morning Giles wakes up and notices that he has turned into a demon.
Buffy becomes familiar with the Initiative and begins to work with them although they are still unaware of her true power as a Slayer. After Buffy abandons her friends at the Bronze for a mission with the Initiative, Buffy and Riley consummate their relationship unaware that they are being watched on a hidden camera by Walsh. Meanwhile, Giles and the rest of the gang remove a tracking device the commandos shot into Spike's back.
Buffy and Riley get mutually suspicious of each other when Buffy reveals that Professor Walsh tried to have her killed. When Professor Walsh is found dead things get even more out of hand, with the commandos quick to blame Buffy. Riley is even more agitated when he sees Buffy with Spike (hostile 17) and then again at Willy's Place. Riley progressively gets sicker and we learn that the commandos have been taking medication to increase their strength. Meanwhile the man-demon-machine Adam that Professor Walsh created is roaming Sunnydale and even Buffy can't seem to stop him.
Faith, still in a coma in the hospital, is dreaming of being pursued by Buffy. Riley, partially recovered from his encounter with Adam leaves the Initiative infirmary and joins up with Buffy. While Buffy and gang plot how to go after Adam, Buffy finds out that Faith has awoken. Faith wants revenge and confronts Buffy. A message from the Mayor and a mysterious device come to Faith through a friend of the Mayor's (a demon who Faith kills). Later Faith goes after Joyce in her own home and of course Buffy arrives to save the day. Faith uses the device with unknown powers before Buffy strikes her down.
After Faith switches bodies with Buffy via the device that was left for her by the Mayor, she begins to slip into Buffy's life. When the police try to take away Faith (Buffy in Faith's body) she is kidnapped by a special group from the Watcher's Council. As Buffy tries in vain to convince them that she is not Faith, Faith in Buffy's body is out having a good time. Willow attempts to introduce Tara to Buffy but when Tara senses that something is amiss they perform a spell which uncovers the switch. The man/demon/machine Adam has determined that his purpose is to kill and recruits some vampires to help. The vampires take over a church and both Faith and Buffy arrive to stop them. Using a Katra that Willow and Tara conjured, Buffy gets her own body back and Faith runs and disappears without a trace.
Buffy and Riley are spending all their time in bed (and they're not sleeping). Their round-the-clock exploration of each other awakens the spirits of children who were sexually repressed by their foster mother back when Lowell House was a home for orphaned and runaway kids. Willow, Giles and Tara divert the angry children while Xander and Anya go to try and stop Buffy and Riley.
Tara and Willow's relationship seems to be progressing when Oz returns to town. Through his travels Oz has found a combination of charms, potions and meditation that allows him to avoid turning into a werewolf. When Oz discovers that Willow and Tara are more than friends he loses control and as a werewolf chases Tara.
Adam enlists Spike to turn the gang against each other, leaving Buffy alone and helpless. Spike plays on their fears of how the others perceive them, telling Xander that Willow and Buffy no longer think that they need him and that he would be better off joining the Army; telling Willow that Xander and Buffy believe her experimenting with magick is just a phase; and elaborating on Giles' own beliefs that he no longer needs to be in Sunnydale. Giles ends up drunk while Buffy, Willow and Xander fight. Angel comes from L.A. to apologize to Buffy after their fight over Faith in 'Angel' but he ends up fighting with Riley. Buffy sees Adam kill Forrest and tells Riley. The distraught Riley goes to confront Adam while Buffy determines she has to face him alone.
Adam tells Riley that he has a behavior modification chip wired to his central nervous system behind his heart. Through the chip Adam has control over Riley. When Buffy find Spike in Adam's cave she figures out that he intentionally tried to split up the gang. Buffy tells the rest of them and the find that Adam wants Buffy to go to the Initiative as part of his plan. Xander suggests that they need the power of all the gang members combined to defeat Adam and Giles agrees. The gang all break into the Initiative.
Buffy comes up with a plan: The gang makes an attack on the First's army, aided by Willow, who performs a powerful spell to imbue all of the Potentials with Slayer powers. Meanwhile, wearing the amulet that Angel brought, Spike becomes the decisive factor in the victory, and Sunnydale is eradicated. Buffy and the gang look back on what's left of Sunnydale, deciding what to do next...