"Phases" begins with Willow's increasing frustration that Oz shows no sign of wanting to get seriousnot to mention physicalwith her. Cordelia is frustrated with Xander because he keeps talking about Willow, even while making out in Sunnydale's lover's lane under a beautiful full moon. They are attacked by a werewolf that rips a hole in the car's roof. Giles points out that there have been quite a number of other attacks, though so far only animals have been killed. During high school gym class, we learn that at least two students have been recently bitten: Oz by a young cousin who doesn't like to be tickled, and school macho Larry by a dog.
After some research, Giles finds out that a werewolf is a wolf for three nightsthe coming night would be the second. Since the werewolf is human the rest of the month, it would be wrong to kill him. This, however, is not what werewolf hunter Cain thinks, whom Buffy and Giles meet while looking for the animal in woods where Xander and Cordelia were making out: Cain is out for his twelfth pelt. Though the two groups do not get along, mainly because Cain is a rampant chauvinist, Giles and Buffy do learn that the werewolf will be attracted to places were teenagers hang outit is the "sexual heat" that draws it.
Buffy and Giles rush to the Bronze, where Cordelia and Willow are busy complaining to each other about their men when the werewolf crashes the party. Buffy tries to catch it with a chain but fails. Cain joins them and points out that it will be Buffy's fault if the werewolf kills anybody.
Theresa Klusmeyer, one of the students that Larry was tormenting, is walking home late at night when she senses someone is following her. She begins to rush and is startled when Angelus steps out in front of her. She's suspicious at first, but when he tells her that he's a friend of Buffy's, she drops her guard. As Oz prowls the night, he has a brief run in with Angelus but the two merely go about their business.
A body does turn up the next morning: Theresa's. Buffy is not the only one to have feelings of guilt. Oz wakes up in the forest, naked and confused after changing back from his wolf state before the viewers eyes. Recalling the bite he got, he calls his Aunt Maureen, and casually asks if his cousin is a werewolf. The answer is yes.
Xander figures that Larry is the most obvious suspect because of the dog bite, aggressiveness and "excessive back hair". When he confronts Larry alone in the gym locker room, it turns out that he really is hiding somethinghis homosexuality. Xander unwittingly helps Larry out of the closet. Larry is then left with the impression that Xander is also gay (when he really isn't). Back in the library, Buffy suggests to Willow that she might have to make the first move if she wants to speed things up with Oz.
Buffy realizes that the reports of Theresa's body didn't mention any mauling. She and Xander get to the funeral home to examine her body and find the bite marks on her neck confirming that a vampire killed her. As they talk, Theresa turns, rises from her coffin and attacks Buffy, passing along greetings from Angelus before Xander stakes her.
Cain busies himself casting silver bullets in preparation for the hunt. Willow takes Buffy's advice and visits Oz just before sundown. Oz is about to chain himself up but lets Willow in the house. Her rant about the mixed signals he is sending is interrupted by him changing into a werewolf. She flees the house screaming, the werewolf in pursuit. Cain hears the wolf's cry and joins the hunt. The werewolf is distracted by a scent which Cain set as a trap, and Willow escapes and then finds Giles and Buffy, who are about to start the hunt for Oz with a tranquilizer gun. All parties meet in a clearing in the forest, and in the scuffle, it is Willow who shoots Oz, saving everybody. Buffy bends Cain's gun with her bare hands using Slayer strength, and tells him to leave Sunnydale.
At school the next morning, Larry thanks Xander, and Willow seeks out Oz to talk. She points out that she is not fun to be around three days out of the month either and she accepts Oz werewolf or human. Oz and Willow share their first kiss, leaving Oz saying to himself "a werewolf in love".
- Actually Pretty Funny: Giles is talking about how the phases of the moon exert a great deal of psychological influence, and the full moon "tends to bring out our darkest qualities." Xander quips, "Yet, ironically, also led to the invention of the moon pie." Buffy and Willow are unimpressed as always but Giles almost cracks up.
- Always a Bigger Fish: Oz in werewolf form follows a trail of blood until he finds Theresa's corpse, Angelus in vamp face standing over her. The two snarl and growl and hiss at each other until Angelus decides he would not like to be torn limb from limb and withdraws.
- Armoured Closet Gay: Larry acts like a lecherous Jerk Jock to hide the fact that he's gay.
- Auto Erotica: Cordelia has this in mind, but Xander is too busy griping about Willow taking up with Oz.Cordelia: Look around. We're in my daddy's car, it's just the two of us, there is a beautiful, big full moon outside tonight. It doesn't get more romantic than this. So shut up!
- Bait-and-Switch Comment: Cordy the morning after she and Xander were attacked in their car by a werewolf.Cordelia: It was so awful. (puts her head on Xander's shoulder)
Xander: (puts his arm around her) I know.
Cordelia: (tears herself away) Daddy just had this car detailed.
- Battle Trophy: Cain has a necklace of werewolf teeth.
- Beware the Nice Ones: Giles is very close to letting out Ripper when Cain keeps insinuating that Giles and Buffy are in the park at night for a tryst. First he goes all Tranquil Fury, then Buffy has to hold him back as he lunges at Cain.
- Break the Cutie: "Angel sends his love."
- Broken Heel: Willow trips while fleeing the werewolf.
- Bully Hunter: When Larry is leering about doing self defense with Theresa, she stammers that there's several members of the group. Buffy; who had played bully hunter on Larry before (in "Halloween") comes to her side, all smiles, and says, "And I'm one of the few." Willow has to spoil her fun and pull Buffy aside, telling her she can't go all Slayer on him. Buffy pouts that Willow is spoiling her fun.
- Bullying a Dragon: After the above-mentioned scene, Buffy pretends to be a weak little girl who can't toss Larry over her shoulder. Larry makes the mistake of grabbing her ass and promptly gets thrown hard onto the mat.
- Cat Fight:Willow: Great. I'll give Xander a call. What's his number? Oh, yeah, 1-800-I'm-Dating-A-Skanky-Ho.
Buffy: (surprised) Meow!
Willow: (smiles) Really? Thanks. I've never gotten a 'meow' before.
- Caught in a Snare: Buffy gets caught in Cain's net trap.
- Coincidental Broadcast: This one via car radio.
- Comically Missing the Point: Xander uses his "hyena-sense" to work out who the werewolf is, and realises the answer is right in front of him. Oz looks alarmed as he's standing before Xander, who says...it's Larry!
- Continuity Nod: Oz notes how a cheerleader trophy's eyes appear to follow him around the room. Xander brings up memories of his hyena possession, and is immediately called out on his Faking Amnesia.
- Delinquent: It appears not all of Buffy's bad reputation is from her Slayer activities.Willow: There is one name that keeps getting spit out. Aggressive behavior, run-ins with authorities, about a screenful of violent incidents.
Buffy: Okay, most of those were not my fault. Somebody else started 'em. I was just standing up for myself.
Willow: They say it's a good idea to count to ten when you're angry.
Buffy: (Death Glare at Willow) One... Two... Three...
- Disarm, Disassemble, Destroy: Buffy bends Cain's double-barreled rifle with her bare hands. Cain wisely decides not to make an issue of it.
- Distinction Without a Difference:Giles: Let's not jump to any conclusions.Buffy: I didn't jump. I took a tiny step, and there conclusions were.
- Distracted by the Sexy: Buffy and Giles are patrolling the local Make-Out Point.Giles: (quietly) Anything yet?
Buffy: Yes. And you won't believe what I saw. Brittany Podell was making out with Owen Stadeel, but he goes with Barrett Williams. (gets a look from Giles) If she ever found... No, um, no, no sign of the werewolf. How about you?
Giles: Uh, the same. (looks around) I thought we might, uh... I thought we might knock on a few windows, uh, ask if anyone has seen anything yet.
Buffy: (gives him a look) Giles, no one's seen anything.
Giles: Oh, yes. No, of-of-of course not, no.
- Does This Remind You of Anything?:Buffy: Welcome to the mystery that is men. I think it goes something like: they grow body hair, they lose all ability to tell you what they really want.
- Everybody Knew Already: After realising he's a werewolf, and that he'd been bitten earlier by his cousin Jordy, Oz gets on the phone.Aunt Maureen? Hey, it's me. Um, what? Oh! It's, uh... actually it's healing okay. That's pretty much the reason I called. Um, I wanted to ask you something. Is Jordy a werewolf? Uh-huh. And how long has that been going on? Uh-huh. What? No, no reason. Um... Thanks. Yeah, love to Uncle Ken.
- Evil Poacher/Straw Misogynist: Cain
- Fantastic Aesop: Werewolves are related to male behaviour...somehow.
- First Willow Kissage: Willow complains that she's not getting any smoochies from Oz; at the end of the episode she takes the initiative and kisses him herself.
- Foreshadowing: Converting a loved one to vampirism so a vampire hunter will be forced to kill them is the tactic Angelus uses against Holtz in the spin-off series.
- Game Face: Threasa when the vamprisim finally completes in her during her way. When she awakens, she's already in vamp face and ready to attack.
- Gayngst: Larry's fear of ruining his popularity and losing his spot on the football team by coming out as gay is probably justified, this being the 1990s, but he also thinks that people are going to "run him out of town" if they knew.
- Getting Crap Past the RadarWillow: I mean, three days out of the month I'm not much fun to be around either.
- Also, Giles calling Cain a "pillock" is the British version of calling him a "dick". The original meaning of "penis" has become somewhat forgotten, but someone like Giles would certainly know.
- Honor Before Reason: Buffy lets Cain leave even though judging by the collection of teeth he's killed dozens of people to get werewolf pelts.
- Hot for Teacher: Xander mentions Ms. Litto, the coach and personal defense teacher, is "kinda hot".
- IKEA Weaponry/Tranquillizer Dart: The tranquilizer rifle.
- Improvised Weapon: Xander stakes Vampire Theresa with an easel.
- I Resemble That Remark!Xander: I just don't trust Oz with her [Willow]. I mean, he's a senior, he's attractive — okay, maybe not to me, but — and he's in a band. And we know what kind of element that attracts.
Cordelia: I've dated lots of guys in bands.
Xander: (nods) Thank you.
- Then Cordelia gets up Xander for babbling on about either Willow or Buffy when he should be kissing her. Xander says he doesn't babble.
- Willow gripes that it used to be easy to tell if a boy liked you, "He'd punch you on the arm and run back to his friends." Xander walks up and punches Buffy on the arm.
- Ironic Echo Cut:Willow: Xander and Cordelia? What could he possibly see in her?(Answer Cut to X/C smooching in their car, but then Xander stops)Xander: What could she [Willow] possibly see in him [Oz] anyway?
- It's Probably Nothing: Cordelia is clearly not thinking. Hearing strange noises while making out with your boyfriend in the woods — it's obviously a monster! Leads to:
- I Warned You: Xander telling Cordelia, 'I told you I heard something'.
- Lampshaded Double Entendre:Larry: Man! Oz, I would love to get me some of that Buffy and Willow action, if you know what I mean.Oz: That's great, Larry. You've really mastered the single entendre.
- Last-Second Word Swap: Cordy is clearly more 'experienced' than Xander.Cordelia: Excuse me? We didn't come here to talk about Willow. We came here to do things I can never tell my father about because he still thinks I'm a... good girl.
- Love Dodecahedron: Lampshaded by Xander when he mutters about how complicated his life is. He's dating Cordelia, is jealous of Willow — who's dating Oz and is equally jealous of them — and is in love with Buffy who's still pining for her boyfriend-turned-evil.
- Make-Out Point: Xander and Cordelia are making out in her car when a werewolf attacks them. The following night Buffy and Giles are searching for the werewolf and Giles suggests knocking on a few car windows and asking if anyone's seen the creature. Buffy gives him a What an Idiot look. "Giles, no-one's seen anything."
- Master of the Mixed Message: Xander and Oz, according to their girlfriends.
- Mistaken for Gay: Inverted, then played straight, when Xander accuses Jerk Jock Larry of harboring a secret (he thinks he's a werewolf), and Larry comes out to him. Since Xander had tried to sympathize by saying he "had been there" (when he was possessed by a hyena), Larry then thought Xander was also gay. Even better, at this point Whedon still hadn't decided on whether to make Xander or Willow gay, and if he had picked Xander, this was going to be Foreshadowing.
- The latter works even better with Xander's panicky reaction when Buffy asks him about Larry:Buffy: So how did it go with Larry?Xander: What's that supposed to mean?!
- The latter works even better with Xander's panicky reaction when Buffy asks him about Larry:
- Mr. Exposition: Guess who.Oz: I spoke to Giles. He said I'll be okay. I just have to lock myself up around the full moon. Only he used more words than that. And a globe.
- Name of Cain: By killing werewolves Cain is also a killer of human beings.
- Nightmare Fetishist: Giles is practically giddy (well, close as he gets, anyway) at the prospect of getting to research werewolves.Giles: Yes, I must admit I am intrigued. Werewolves, it's... it's one of the classics. I'm sure my books and I are in for a fascinating afternoon. (leaves)
Buffy: He needs to get a pet.
- Not What It Looks Like: Giles is indignant when Cain assumes he's out in the woods with Buffy for some underage nookie.
- Oblivious Mockery: Cain tells Giles he looks like someone auditioning for the job of librarian.
- Oblivious to Love: Willow wants her kissage now, please!Buffy: Have you dropped any hints?Willow: I've dropped anvils.
- One Dialogue, Two Conversations: The morning after Buffy finds out Oz is a werewolf and Xander discovers Larry is gay.Xander: This is all so weird. I mean, how are we supposed to act when we see him?
Buffy: Well, it's gotta be weird for him, too. Now that we know so much.
Xander: All I know is I'll never be able to look at him the same again.
Buffy: He's still a human being. Most of the time.
Xander: Who are we talking about?
Buffy: Oz. Who are you talking about?
Xander: No one...
- Out-of-Character Moment: Giles is explaining that the full moon brings out the darkest in people, and Xander quips, "And yet, ironically, led to the invention of the moon pie." Rather than snapping at Xander, which is what he always does, Giles giggles appreciatively! This is probably a deliberate use of the trope; the joke is that having spent a year deriding Xander's impertinence, he finds the humour in this singularly lame remark. (He's the only one, by the way.) Giles' unusual behavior in this episode also reflects his unusual mood - he is excited at the opportunity to encounter and research a werewolf, which he refers to as "one of the classics."
- The Profiler: Spoofed when Willow determines the most likely werewolf candidate is Buffy due to her history of violence.
- Red Herring: Larry behaves like a lecherous Jerk Jock and states that he was badly bitten by a dog recently - but it turns out, he's not the werewolf.
- Red Shirt: Theresa exists mostly to be a victim of Angelus, get turned and have to be staked.
- Rise from Your Grave: Theresa turns during her wake and rises out of her coffin not shortly after Buffy and Xander come to examine her body.
- Saying Too Much: Both Played for Laughs...Xander: I'm practically an expert on the subject.
Willow: On account of once you were a hyena?
Xander: I know what it's like to crave the taste of freshly killed meat, to be taken over by those uncontrollable urges.
Buffy: You said you didn't remember anything about that.
Willow: I don't want to be the only girl in school without a real boyfriend. (reaction Buffy) Oh, I'm such an idiot. I'm sorry. I-I shouldn't even be talking about... Do you want me to go away?
- ...and Played for Drama.
- Sex Is Cool: Having been a socially-isolated nerd all her life, Willow is eager to get started on the smoochies like other girls her age are doing.
- Scare Chord: "Why so jumpy, Larry?"
- Shaped Like Itself: Loads of this.Willow: Well, last night was the night before the full moon, traditionally known as... 'the night before the full moon.'(And also)Xander: You're Buffy. Eradicator of Evil. Defender of...things that need defending.(Willow reporting that Oz is a werewolf)He-he said he was going through all these changes. Then he went through all these... changes.
- A Shared Suffering: Cordelia and Willow bond by griping about their boyfriends. Xander is justifiably nervous.
- Ship Tease: Buffy gives Xander a long hug after he saves her life. Given that Angel is out of the picture, Xander is clearly hoping this will lead to something more, but Buffy just walks away.
- Shoot the Messenger: Theresa's death and turning was meant as a form of this to Buffy.
- Xander and Cordelia are attacked by the Monster of the Week while making out in a car, in true horror movie tradition. It's Xander, however, who hears the strange noise and Cordelia who insists it's nothing, in true Buffy tradition-defying tradition.
- The scene where Buffy throws a lecherous boy who grabs her behind was in the original Buffy the Vampire Slayer movie.
- The sequence in which Oz wakes up naked after his first rampage is an exact shot-for-shot homage of the sequence in which David wakes up after his first night as a werewolf in An American Werewolf in London.
- On being reminded that werewolves are people, Buffy promises to Bring 'Em Back Alive.
- Shrinking Violet: From what we see of Theresa, she seems very anxious and uncertain of herself, though kind of sweet. It's a shame she runs into Angelus.
- Averted with Willow who's starting to get more assertive about what she wants.
- Silver Bullet: Cain is shown casting his own bullets.
- Staking the Loved One: Angelus turns a schoolmate of Buffy's, Theresa, into a vampire, knowing that she'll be forced to stake her when she goes to examine the corpse.
- Stating the Simple Solution:Coach: Sunnydale is becoming more dangerous all the time. And a full moon like tonight tends to bring out the crazies, but with some simple basics of self-defense each of you can learn how to protect yourself.
Buffy: (sotto voice) Here's a suggestion: move away from the Hellmouth.
- The Stoic: Oz upon realising he's a werewolf. "Huh!"
- Stuffed into the Fridge: Theresa is a previously unseen "friend of Buffy's" introduced just so Angelus can vamp her to mess with Buffy's head. She even wears a red blouse!
- Super Window Jump: The werewolf escaping from the Bronze.
- Suspiciously Specific Denial: Buffy notices Larry is acting strangely.Xander: What, it's not okay for one guy to like another guy just because he happened to be in the locker room with him when absolutely nothing happened and I thought I told you not to push?
- Terror At Makeout Point: Which doesn't stop anyone from snogging there the next night.
- Took a Level in Badass: First Xander, then Willow end up saving Buffy.
- Took a Level in Kindness: Larry accepts his homosexuality and stops acting like a Jerkass.
- Two Scenes, One Dialogue: Larry demands that Oz reveal how far he's gone with Willow. Cut to Willow saying, "Nowhere!", indignant that Oz hasn't even got to kissing, let alone sex.Buffy: It's nice that he's not just being an animal.
- Van Helsing Hate Crimes: Cain, although he's motivated by greed rather than fanaticism. He's well aware the wolf he's hunting is an innocent person most of the time, he just doesn't care.
- What the Hell, Hero?: Cain tries to pull this on Buffy, claiming she lets more people die then she does to save them.