Sunnydale High is re-opened, with a new designed campus and a new principal, Robin Wood. It is Dawn's first day at school there and Buffy accompanies her to class, only to discover evil spirits lurking in the basement.
Though they seem to be in the same places at the same time, Buffy, Xander and Dawn are unable to find Willow when she returns from England. Shortly after returning to Sunnydale, people start turning up skinned alive. As Buffy and Xander worry that this could be Willow's work, Willow sets out to find the creature that did it.
Anya grants a young woman's wish, and the violent and deadly act of vengeance leaves everyone stunned. Buffy must put aside her feelings for her friend and take action before more people die. Meanwhile, flashbacks depict how Anya became a vengeance demon, and Willow returns to college.
Dawn's simple crush on Sunnydale High's star quarterback RJ starts to become obsessive, leading Buffy to investigate the boy herself. When Buffy, along with all the other women who see RJ, also fall in love with him, Spike and Xander must team up to discover the source of this attraction. But first they have to keep the women from doing anything crazy in their competition for RJ's affection.
Buffy has a conversation with a vampire who once went to Sunnydale High, and learns something interesting about Spike. Joyce materialises to Dawn in the living room. The ghost of Cassie brings a message to Willow from beyond the grave. Meanwhile, Andrew and Jonathan have returned to Sunnydale on a mission to save the town
Spike is held captive in the Summers home while the Scoobies ponder their options in the aftermath of his murder spree. Willow finds Andrew buying blood and decides to take him prisoner also. While they try to decide what to do next, the gang are interrupted by the mysterious hooded figures called "Harbingers"... the minions of the First Evil.
Giles returns to Sunnydale with three potential slayers, whom Buffy must protect from The First. Meanwhile, a ferocious Uber-vampire is released from the Hellmouth and Buffy must kill it before it kills one of the potentials.
Buffy teaches the Potential Slayers a valuable lesson as she faces a final fight with the Uber-vampire. Meanwhile, Giles and Anya enter another dimension to find a demon which holds the answer the defeating The First. What they find out is very disturbing.
Buffy takes the Potentials to a demon bar and then to Spike's crypt, in order to teach them the art of slaying. When Willow casts a spell to seek out the next Potential, the spell leads them to believe that Dawn may be a future slayer.
After Willow and Kennedy share their first kiss, Willow is transformed into Warren, the man she killed last year. When she sets out to find help, she bumps into an old friend. Meanwhile, Buffy searches for answers when Spike's chip causes him great pain, and the gang suspect that Giles may really be The First
Buffy accepts an invitation to dinner from Principal Wood, and the secrets of his past are revealed. Xander impresses a beautiful girl with his knowledge of knots, and she seems to be interested in tying him up. Meanwhile the First contacts Andrew in another attempt to destroy the Potentials, and Giles finds himself tongue-tied with the new Potential, Chao-Ahn.
The Scoobies use a spell to transport Buffy into a shadow world, where she meets the men who created the first slayer. However, in order for her to return home, the gang must find and slay a ferocious demon
Andrew creates a documentary called "Buffy, Slayer of the Vampyres", a record of the current situation in Sunnydale to show to future generations. He manages to capture many important moments, and to annoy almost everyone in the house. But Buffy needs to tear him away from his filmmaking because the Seal of Danzalthar is active and Andrew may hold the key to closing it before it destroys the town.
Faith returns to Sunnydale just as a new villain, Caleb, arrives and sends Buffy a message in the form of a badly beaten Potential. Buffy leads the rest of the girls to Caleb and The First's lair, with devastating consequences.
Buffy has a powerful new weapon, but the gang cannot find any information about the origins of the mysterious scythe. Eventually the Slayer goes herself in search of knowledge, and finds a new ally, an old friend, and great danger.
After killing Caleb, Buffy conceives a plan to defeat the First once and for all. Willow invokes a magic spell that alters the ancient Slayer spell and gives Buffy the allies she needs to fight the Uber-Vamp army. An epic battle ensues and several good friends are lost. At the end, Buffy faces a completely new problem -- one she's glad to have.