Buffy and Angel finally agree to a date, but Buffy is delayed at Pop's Pumpkin Patch by a vampire. Another vampire films while hiding. As Angel waits at The Bronze, Cordelia shows up and starts talking to him. When Buffy finally arrives, she is turned away by Cordelia's sharp tongue. Cordelia continues to hit on Angel, unaware of his history.
The next day, Principal Snyder forces Buffy and her friends into chaperoning small children while they trick-or-treat. Buffy would rather take a break during the only slow night for vampires. Later, Larry, the school bully, threatens Xander while asking him about Buffy, who smashes Larry into a soda machine. Xander is angered by the damage that does to his reputation.
After Xander leaves, Buffy and Willow's conversation eventually turns to speculation about Angel's past. The two decide to sneak into Giles' office and borrow the passed down Watcher's Diary. From this, they hope to learn more about what type of girls Angel used to be attracted to as a human. Buffy is slightly mopey after her date with Angel didn't fly, and is eager for information on how to win him over.
The gang has to dress up for Halloween. They head to Ethan's Costume Shoppe, where Willow gets a ghost costume and Xander buys a toy gun to go with his army fatigues from home. Buffy and Xander make up, but then she spies the most beautiful 18th-century pink dress - one that matches what she has spied from Giles' Watcher files on Angel. Ethan Rayne appears and makes her an offer she cannot refuse.
Spike is reviewing Buffy's fight. Drusilla comes to tell him that someone will make Buffy weak on Halloween night. Meanwhile, Ethan is chanting to a statue of Janus in the back room of his shop.
On Halloween night, Buffy manages to convince Willow to wear a black mini-skirt and a long-sleeved crop shirt. Willow is very shy and tries to hide it with her ghost costume. The doorbell rings and Willow takes the opportunity to cover her skimpy outfit. Later that night, Ethan's spell takes effect and everyone wearing a costume from his store turns into the respective persona. Willow becomes a real ghost, able to walk through walls, Xander a soldier and Buffy an 18th-century noble woman.
Willow convinces Xander to stop shooting at people. They find a disoriented Buffy, who is frightened and confused by the modern world. Willow rushes them to Buffy's house, where her mother is conveniently not home. Outside, Cordelia screams and Xander rushes out to save her. They find that Cordelia has not changed into what she is wearing - a cat - because she bought her costume from another store. Willow goes to Giles for help. While Cordelia searches the house, Angel shows up and takes Buffy into the kitchen. As Angel tries to kill a vampire that has sneaked into the house, he reveals his vampire face. Buffy is horrified and runs from the house.
Arriving at the library by walking through walls, Willow, after scaring Giles by just showing up where there isn't a door, tells him about Ethan's costumes. They head to the shop, where Giles reveals that he knows Ethan. He orders Willow to leave and physically persuades Ethan to tell him how to reverse the spell.
Spike is looking for Buffy, who enters an alley and meets Larry, now a pirate. Xander arrives to beat up Larry while Willow shows up to warn them of Spike. The gang tries to barricade themselves inside a warehouse, but Spike's gang breaks in. Just as Spike is about to kill Buffy, Ethan reveals the secret to ending the spell and Giles throws the statue to the floor, smashing it to pieces, breaking the spell. Buffy recovers to defeat Spike and he flees.
Oz sees Willow around town again, asking himself "Who is that girl?"
Buffy admits to Angel that she was trying to impress him. He tells her that he hated those people back then. The women were dull; he wanted someone exciting. They kiss. The next day, Giles returns to the store to find a note. Ethan has promised to return soon.