Old and new friends gather at the Summers home for Buffy's 21st birthday party and it goes off without a hitch - mostly. Feeling neglected by Buffy and the Scoobys, Dawn's wish to keep people from leaving her is answered by Anya's demon friend Halfrek, who binds the attendees of the party to the house. When Tara tries a spell to free them, she only makes the situation worse by accidentally releasing a demon trapped inside a sword.
Buffy Summer's journey as the Vampire Slayer begins when she moves to Sunnydale, a small Californian town that, unbeknownst to most residents, sits atop a Hellmouth - a portal to supernatural forces. She is discovered by Rupert Giles, the school librarian and her Watcher, whose role is to guide and train her as the Slayer. Alongside Giles, Buffy forms an eclectic group of friends, her "Scooby Gang", including Willow Rosenberg, a shy but highly intelligent witch; Xander Harris, Buffy's best friend and comic relief; and Cordelia Chase, a popular girl who becomes a reluctant ally.
Buffy's relationships with those around her, particularly romantic entanglements, are a major focus of the series. Her most notable love interests are Angel, a vampire with a soul, and Spike, who, despite being a villain, develops a complex and evolving bond with Buffy. The complexities of her relationships, particularly her love life, highlight the emotional weight of Buffy's duties as the Slayer and her desire for connection, love, and a sense of normalcy.