It's Halloween, and the Magic Box is enjoying its busiest day ever, to Anya's delight. Xander goofs around pretending to be a pirate, Dawn looks for stuff to take, Anya roller-skates around selling things, while Willow argues with a woman who is dressed as a stereotypically evil witch—Willow insists that that is a misrepresentation. Buffy runs into Spike in the basement, and the two have an awkward conversation in which Buffy thinks Spike is trying to get her into bed, but then he clarifies that he wants to go patrolling with her that night, notwithstanding the fact that supernatural forces typically don't operate on Halloween. The gang, who have been helping out all day, are worn out. Anya dances with Dawn as she counts her money. Xander looks at her, and decides that the time has finally arrived to announce that he and Anya are engaged. The gang wishes the couple well but privately share their concerns with each other. As Anya gushes about wedding plans and being married, Xander starts to look uncomfortable.
The gang throws an impromptu party at Buffy's house for the two. When the lack of decorations is mentioned, Willow uses a spell to fill the room with them. While Anya is grateful, Tara and Giles share a concerned look.. Later in the kitchen Tara tries to talk to Willow about her casual and increasingly excessive use of magic, while Willow fails to see anything wrong with doing so. Dawn reminds Buffy that she is spending the night at her friend Janice's house. After Buffy approves, Dawn heads out to meet Janice for what is actually planned to be an evening of Halloween fun and teenage hijinks with two older boys named Zack and Justin.
As Dawn, Janice, Zack, and Justin engage in some of the more violent Halloween pranks, breaking windows and damaging mailboxes, back at Buffy's place, Giles and Xander share a drink and talk about Xander's future. Xander almost seems to second-guess his marriage intentions and his future. Giles assures him that everything will be fine.
Dawn and friends find themselves in front of Old Man Kaltenbach's house, Kaltenbach being reclusive and subject to rumor. After Janice refuses to approach the house, Dawn then bravely volunteers. Unfortunately, as she lifts his pumpkin to smash it, the old man grabs her. Dawn's pals quickly rush her aid and are... cheerily invited into the house. As it turns out, the man was actually a toy maker who is merely bitter about his toys becoming obsolete. Justin offers to help the old man with his special treat in the kitchen. As he prepares rice crispy treats for the kids, Justin vamps out, kills the old man, and steals his wallet. Zach and Justin debate whether to just eat Janice and Dawn, or turn them into vampires, too. Justin gives Dawn $10—her portion of the money stolen from Kaltenbach, which she accepts without hesitation. When Justin discovers that Dawn has been stealing for a long time, he is impressed after hearing her out.
Janice's mom calls Buffy's house. Quickly, Giles figures out that Dawn has tricked them. Xander refers to it as "dipping into the classics". Giles goes off to find Buffy; Anya, and Xander mind the house; and Tara and Willow head for The Bronze. Zack steals a car by killing the driver. Then, the four teens begin making out. Janice and Zack then take off, leaving Dawn and Justin alone in the car. Justin then takes the opportunity to make his move and deliver Dawn her very first kiss.
At The Bronze, Tara and Willow get into a fight when Willow proposes to magically shift everyone who isn't a 15 year old girl old into an alternate dimension to make Dawn easier to find. After Tara calls Willow out, Willow gets very angry and accuses Tara of taking Giles's side.
In Zack's stolen car, Dawn and Justin continue to make out. However, after Justin nibbles her lip a little too hard, he vamps out. Although Dawn is swept away in the moment, she manages to feel his lumpy noggin. Nearby, Buffy smashes the door in on Spike's Crypt. He informs her of Dawn and her antics. Buffy, angry, grabs a pistol crossbow out of Spike's weapons chest.
In the cemetery, Giles hears a girl scream and races to save her, thinking it's Dawn. Instead, he finds Zack and Janice, just as Zack pulls his teeth out of her neck. Zack calls Giles "grandpa" and tells him Janice was asking for it. The Watcher scoffs that he's certain she was not, and then dusts him. He continues to look for Dawn.
Meanwhile, Dawn has just run out of the car to get away from the vampire. He stops her, telling her in an unconvincing monotone that she's different from other girls; he could tell when he first met her that she was special. As he leans in to bite her, he says that it's OK and that it will only hurt for a second. At that moment, Giles finds Dawn and tells her that Justin says that to all the girls. As Giles approaches to fight him, a crew of vampires, surround them.
Just then, Spike and Buffy also arrive on the scene, and Buffy turns into her mother as she criticizes Dawn for parking with a vampire. Dawn protests that she didn't know he was a vampire; they'd just met. Buffy counters angrily that she shouldn't be parking with a guy she just met, and Dawn protests that Buffy fell in love with a vampire. Then, an all-out Halloween battle breaks out. In the battle's conclusion, Justin finds Dawn, knocks her down, and straddles her. She says she thought he really liked her. He says he does, then leans in to bite her. But Dawn dusts him with a crossbow arrow she was holding at her waist.
The gang return home, where Buffy is quick to leave the job of chastising Dawn to Giles, who is unhappy about how Buffy is relying on him so much. Meanwhile, Tara is still angry at Willow, so Willow casts a spell on Tara to make her forget their quarrel.
This episode means that all three of the Summers women have had romantic encounters with vampires — Buffy with Spike and Angel, Joyce meeting Dracula for coffee and now Dawn with Justin.
This episode makes use of misdirection by setting up Kaltenbach as the main villain, only to have him anticlimactically killed by Justin.
When Willow and Tara are discussing Willow's increased use of magic, Willow uses a spell to mute everyone; "Sekaat", which is "Silence" in Arabic. Then, when Tara unmutes everyone she says "Takalam", which is "Talk" in Arabic.
When asked to get more Mandrake Root from the basement, Buffy comments that it won't be her fault if they "have this conversation over and over" and over again, a reference to the time loop in the previous episode ("Life Serial").
Xander's eye patch with his pirate costume foreshadows his eventual loss of an eye ("Dirty Girls").
Giles sees that Buffy is becoming too reliant on him; this leads to his decision to leave Sunnydale in the next episode.
Willow erases Tara’s memory in this episode, and when she realizes that, it will influence her decision to end her relationship with Willow over the next two episodes.
This episode also contains some early signs that Xander is unsure of his decision to marry Anya, which later reaches its climax in the later episode "Hell's Bells".
Dawn and her friend joke about fooling their parents/Buffy by telling each of them that they’re at the other’s house, and they can't believe how stupid they were to fall for it. This mirrors Buffy telling Giles she was with her mother and telling her mother she was with Giles, when she was really with Angel — as well as the "round robin" that Buffy, Willow, and Xander all did during high school in order to cover demon research and fighting (in the Season 2 episode "Surprise").
Spike’s coming down on the vampires for not taking Halloween off is a bit hypocritical. Back in Season 2’s Halloween, he made an attempt to kill Buffy during the chaos caused by Ethan Rayne.
Dawn dusts her first vampire in this episode.
Dawn mentions her increasing kleptomania that begun in "Forever" (although it is possible she could be lying about stealing lipsticks). The mention of stealing lipsticks is also a call back to when Buffy said to Merrick in the flashback of Becoming, Part One that she “meant to pay for that lipstick”.
Willow continues to abuse magic.
Justin attempts to court Dawn by giving her his jacket, just as Angel did with Buffy in "Teacher's Pet" and Ripper steals a coat for Joyce in "Band Candy". Dawn would later fall for another Letterman jacket wearing boy, RJ in "Him".
Buffy scolds Xander when she mistakenly believes he wants to marry Dawn. In Season 8, he and Dawn will begin a relationship, much to Buffy’s dismay.
Standing in front of the old man's house, Zack says to Janice, "Pumpkins. Very dangerous. You go first". This is a variation of a quote from Raiders of the Lost Ark, when Sallah sees the snakes in the Well of Souls and tells Indiana Jones "Asps. Very dangerous. You go first".
When Willow and Tara go to the Bronze, Willow references Star Wars saying "Do they know they're brother and sister?" referring to the couple dressed as Luke and Leia erotically dancing.
During Buffy's fight with the vampire by the car, the vampire breaks a car door window with several shards left across the rim of the window. But then Buffy pulls him through the window, the shards have disappeared.
Buffy mentions having been "out of commission for 3 months", but, previously, in After Life Spike says she's been gone for 147 days -about 5 months.
When walking with Justin, Dawn says that she is a freshman, despite the numerous references to Buffy having been gone all summer and her having been a freshman in season 5.
Dawn was 14 in season 5, which on average would put her in 8th grade.
Giles - "Yes, well, if anything calamitous should happen, history suggests it’ll happen to one of us."
Buffy - "Right, exactly, so I should patrol to avoid any of that — and I’m bagging."
Giles - "Brooms all around then."
Willow - "Or I can wip up a jaunty self-cleaning incantation. It'll be like Fantasia.
Giles - "We all know how splendidly that turned out for Mickey."
Willow - "I think I'm a little more adept than a cartoon mouse."
Anya - "How 'bout you, ever play 'Shiver Me Timbers'?"
Tara - "I'm not really much for the timber."
Anya - "We're running low on mandrake root. Check the basement."
Buffy - "Don't blame me if we have this conversation over and over ... and over ... and over, and over."
Dawn - (about Old Man Kaltenbach) "Isn't he supposed to be... mental or something?"
Zack - "Total Looney Tunes."
Dawn - "I-I kiss all the time. Not that I’m a kiss slut — just, you know, with-with the lips and-and the pressing together and stuff. Hey, expert here." (sees Justin’s look) "Okay, okay, it was my first kiss."
Buffy - "Were you parking?! With a vamp?"
Dawn - "I-I didn’t know he was dead!"
Justin - "Living dead."
Dawn - "Shut up!"
Buffy - "How could you not know?"
Dawn - "I just met him!"
Buffy - "Oh! Oh, so you were parking in the woods with a boy you just met."
Carl - "What is your malfunction, man?!"
Spike - "It’s Halloween, you nit! We take the night off. Those are the rules!"
Carl - "Me and mine don't follow no stinkin’ rules! We’re rebels!"
Spike - "No. I’m a rebel. You’re an idiot." (shoots Carl with a crossbow, dusting him) "Give the lot of us a bad name."
Giles - "Mist, cemetery, Halloween... This should end well."