Two police officers rush into the library. From the looks of things, they believe that Buffy has just murdered Kendra. They take her outside, where Principal Snyder arrives with several more cops. Before one of them can cuff her, Buffy knocks the guy down and flees the scene. After disguising herself in a coat and black cap, Buffy goes to the hospital and runs into Xander, who is now wearing a cast on his right forearm. They go to Willow's room, where she lies motionless in a coma. Cordelia arrives, and Buffy learns that Giles was neither with her or in the hospital. Giles has been taken to the vampire's mansion hideout, where Angel hopes to force the necessary info concerning the ritual out of the Watcher. Meanwhile, Joyce learns from the police that her daughter is suspected of murder and that she's a fugitive from the law. Buffy goes to Giles apartment to see if he's there, but instead meets Whistler, who has been waiting inside. He tells Buffy that Angel was destined to stop Acathla, not revive him. However, Buffy's relationship with Angel changed all that. Buffy leaves before Whistler can tell her how to stop the demon. Outside, a patrolling officer recognizes Buffy and orders her to freeze. Suddenly, Spike arrives and beats the cop into unconsciousness. He wants Buffy's help in stopping Angel so he can have Drusilla back the way she used to be, in exchange for his leaving town with Dru and never returning. After some hesitation, Buffy decides to take him back to her house so they can plan their attack. They get there just as Joyce is pulling into their driveway. As Buffy tries to make up an excuse for Spike's presence, a vampire that has been spying on them attacks. Right in front of Joyce's eyes, Buffy stakes the vampire spy, turning him to dust. Realizing what she has to do, Buffy confesses to her mother that she is a vampire slayer.

At the hospital, Xander pleads to Willow for her to wake up. She finally snaps out of her coma just as Xander says that he loves her. The first word out of her mouth is Oz's name, who arrives to greet her back to consciousness. Meanwhile, Giles refuses to divulge the information that Angel needs to properly perform the ritual, so more torture ensues. Back at the Summers home, Buffy and Spike agree to work together, but only on the conditions that Dru can leave with Spike, and that Giles survives. After Spike leaves, Joyce begs her daughter to explain everything that's going on. Buffy tells her mom that there's no time to explain it all, which furiates Joyce. Joyce doesn't want her daughter to be in charge of saving the world, to which Buffy responds that she never wanted the duty in the first place. Joyce tries to restrain her daughter from leaving the house, but Buffy pushes her back against the kitchen counter. Joyce tells Buffy to never come back should she walk out the door, but Buffy leaves anyways.

At the hospital, Willow tells the others that she is going to try the curse again. Buffy returns to the library to retrieve the sword that Kendra brought. Principal Snyder finds her there and promptly expels her due to all the trouble she's been involved in. After Buffy leaves, Snyder calls someone to tell the Mayor that he has good news. Meanwhile, Drusilla tricks Giles by making herself look and sound like Jenny Calendar in his eyes. Giles says that Angel's blood is the key to the awakening ritual. Homeless and expelled, Buffy has only one path to follow now. She returns to Giles apartment and asks Whistler how to use the sword. He tells her that only Angel's blood can open and close the vortex to Hell. With one blow, both Angelus and the demon Acathla would be sent back to Hell, and the vortex would be closed.

Xander catches up with Buffy on her way to the mansion. She tells him to concentrate on freeing Giles and escaping. Xander does not inform Buffy that Willow is attempting the curse again. Inside the mansion, Angel slices his hand and approaches the sword in Acathla's chest. Suddenly, the ritual is interrupted by Buffy's arrival. Angel doesn't even notice Spike rising out of his wheelchair from behind. While Spike brutally beats Angel to the floor, Buffy takes one of the other vampires in the room. During this battle, Xander unties Giles and gets him safely outside. Spike doesn't get too many hits off before an enraged Drusilla jumps into the fray, tackling Spike. While they fight, Angel manages to get back up and run to Acathla. Just as Buffy drives a stake through the vampire's heart, Angel grabs the sword with his bloody hand and finally pulls it out. Swords in hand, Buffy and Angel engage in a sword duel. Elsewhere, Willow, Cordy, and Oz perform the curse of restoration. Suddenly, Willow loses control of her actions and seemingly becomes possessed by some spirit. Cordy and Oz watch in fright as Willow performs the curse herself in perfect Latin. Spike subdues Drusilla and takes her with him as he escapes from the mansion in his car. After the long duel, Buffy finally backs Angel up against Acathla. Just as she is about to deliver the final blow, Willow completes the curse, restoring Angel's soul to his body. Buffy lowers her sword as she realizes the change, and the two lovers are finally reunited. However, it is too late, for Acathla is now awake. Buffy looks over Angel's shoulder and sees Acathla's mouth creating a vortex to Hell. Angel has no idea what is going on, so all that Buffy can do is give her lover one last kiss before driving the sword through his stomach, thus releasing the blood needed to close the vortex and send the two demons back to Hell. Shocked, Angel reaches out towards Buffy with his right hand, but nothing can be done now. Buffy watches as the vortex closes around Angel, leaving the demon Acathla as nothing more than a silent statue once again.

Buffy goes home and packs up her belongings without Joyce ever knowing she had returned. When Joyce enters the room, she finds a farewell letter from her daughter left on the bed. At Sunnydale High, nobody knows what happened to Buffy and Angel. Some believe that Buffy had to kill Angel before the curse was completed, while others believe that Angel has been restored and they were taking time off to be alone together. Unbeknownst to them, Buffy is standing far away by one of the trees, giving her school and her friends one last look before hopping on a bus. The bus heads out of Sunnydale, and Buffy faces an unknown future.