"Uh oh, Daddy's home," jeers Willow as Giles enters the magic shop. He's there to help, and soon binds Willow under a stasis spell. Buffy and Anya embrace him, relieved to have him home. Giles heard from a coven in England about the rise of a new power in Sunnydale, and his magic is being funneled from the coven. Buffy gives him a quick rundown of everything that's happened since he left, and his reaction is totally unexpected: uncontrollable laughter. After finally calming down, Giles feels terrible about abandoning everyone, but Buffy admits it was the right choice. While they try to come up with a way to help their friend, Willow appears in the doorway with an unconscious Anya suspended in front of her. Will used her dark mojo to convince the vengeance demon to release her from the stasis spell.
Xander, Dawn and the nerds walk the dark streets, brainstorming for a place to hide. The subject of Spike comes up, and Xander lets it slip that the Vamp tried to rape Buffy. Dawn is incredulous, and refuses to believe it at first. Meanwhile, Spike defeats some more nasty demons, and his next test is to be covered with a horrific swarm of insects. Fun stuff.
Back at the decimated Magic Box, Willow is still going strong after a long fight with an exhausted Giles. She nearly brings the ceiling down on him, but Buffy shoves him out of the way just in time. "You're always saving people. It's kinda pesky," Willow laments. Willow creates a flaming comet and sends it out to destroy Jonathan and Andrew. Despite her desire to stay and protect Giles, Buffy chases after it to warn the geeks before they're killed. Willow then pounds Giles with magic, finally draining him of the coven's power when she's running low. Through the magic, Willow becomes attuned to the pain of the world and is overwhelmed by its magnitude. Now she has a new purpose: to end that pain, and the world along with it.
At Sunnydale's cemetery, Xander and Jonathan try to break into mausoleums for a place to hide. Dawn spots Willow's flaming comet streaking towards them, and it's only Buffy's timely arrival that saves the nerds. The comet smashes into the ground, knocking Xander unconscious and dumping Buffy and Dawn into the catacombs beneath the graveyard. They're trapped. Jonathan and Andrew are no help, running off screaming into the night.
Anya awakens and finds Giles on the floor of the shop, dying. She teleports to the catacombs and tells Buffy and Dawn the news about the watcher, which spurs Buffy's efforts anew. However, from a distance, Willow thwarts her progress by unleashing corpse-like monsters on the girls to keep them occupied. For the first time, Buffy asks for Dawn's help, and in return, Dawn fights brilliantly. She has learned from the best.
On a mountaintop, Willow draws power from an unearthed temple of the powerful she-demon Proserpexa. Willow is interrupted by Xander, who declares he knows she's going to end the world, but wants to spend his last moments by his best friend's side. He tells her how much he loves her in spite of everything she's done. Willow lashes out at Xander again and again, but his devotion eventually breaks down her barriers. Collapsing in tears of anguish, Willow falls into Xander's arms, her hair and eyes returning to their normal color. It's over.
In the catacombs, Buffy and Dawn are astonished when their corpse foes drop to dust. Buffy begins to sob with joy, and tells Dawn she wants to show her the good things of the world instead of shielding her from its horrors.
Back at the Magic Box, Anya's delighted when Giles awakens. He explains that the magic Willow drained from him deliberately tapped into what was left of her humanity, and Xander is the one that made it happen. Anya is amazed when she realizes her ex saved them all.
As the Scoobies regroup in pairs, Spike is alone in Africa, exhausted and injured. He has finally achieved his goal: to go back to the way he once was. But everything does not go according to his plan. As it turns out, the demon doesn't remove the chip; instead, he returns Spike's soul.
Summary from Buffy.com