At the beach, the Sunnydale High swim team is celebrating their latest victory, while Xander complains about having such a celebration just for the swim team. Buffy sulks on a rock, watching the ocean. A guy named Cameron Walker approaches Buffy and starts sputtering out poetic words. Buffy tries to scare him off, but he says he's looking to talk. Meanwhile, Jonathan Levinson is being dunked in a bucket of ice water by members of the team. Buffy rescues him and scares off the two bullying swimmers. The bullies, Dodd McAlvy and Gage Petronzi, walk off and talk about how weird Buffy seems to them (not knowing about her being the Slayer). Then Dodd stops, while Gage Petronzi keeps walking. Gage then smells something bad but keeps going. He walks by without seeing Dodd's skin, which is lying on the ground but with nothing left inside. We see a creature walk through the sewer.
The next day, Willow Rosenberg is teaching a class, and as she is walking around checking people's work on their computers, she sees Gage playing solitaire on his computer with naked women on the cards. She tells him off, but he doesn't seem to care. After class, Principal Snyder tells Willow that they can't get a new teacher for a while, and that she will have to continue covering (which pleases her). Willow then informs Snyder that Gage is failing because he doesn't show up for tests or do homework. Snyder is not interested; he tells her that, as Gage is on the swim team, he shouldn't be expected to do homework or take tests. Snyder demands that Willow change Gage's grade from an F to a D. Buffy comes to school with Cameron, and he tries to grope her. She hits his head against the steering wheel and breaks his nose. Snyder happens to see this; he and Cameron blame Buffy for the altercation. Cameron tells the Swim Team Coach and Snyder that Buffy was leading him on; the Coach, after telling Nurse Greenleigh to "take care of my boy", turns to Buffy and tells her she shouldn't dress so provocatively.
Later, Buffy rants to Rupert Giles and her friends about the incident with Cameron. Giles informs her that they found Dodd's remains on the beach. Cameron hits the sauna and\ hears some weird noises. The Coach bursts in and announces that Cameron has had enough. While everyone studies in the library, Xander goes out for a drink. Heading for the vending machine, he bumps into Cameron. Xander teases him for getting beaten by Buffy after he tried to paw her. Cameron heads off to the cafeteria for a snack, while Xander tries to decide between grape and orange soda. Cameron screams, and Xander rushes into the cafeteria. He finds the place in shambles, with Cameron's skin on the ground. Xander turns around and finds himself face-to-face with the creature responsible: a Gill Monster.
In the library, Cordelia Chase sketches the creature that Xander saw before running off "like a woman". Buffy and Willow return, having been informed that Cameron and Dodd were the two best swimmers on the Boys' Team; after them was Gage. Buffy is assigned to shadowing Gage - suspecting that he will be attacked next - while Willow interrogates Jonathan under a lamp. According to Jonathan, he indeed wanted revenge, but achieved it in a very different way: by relieving himself in the pool, oddly enough. Xander, who has been teased for his cowardice by Cordelia, overhears Marin and Snyder chatting. They need another swimmer, or they won't be eligible for competition; they don't even care if the guy can swim a stroke, so long as he shows up for practice. The next day, Gage grows suspicious of Buffy when she follows him around. At the Bronze that night, Buffy is confronted by Gage; she attempts to cover it up, but fails. She tells him that his life is in danger, but he ridicules her by calling her a "psycho bitch" and a "head tripper", unknowing of what Buffy really is. He leaves, only to encounter Angelus in the parking lot. They complain briefly about Buffy, then Angelus vamps out and tries to vamp him. However, seconds later, Angelus stops and spits the blood out. Buffy comes to Gage's rescue. A now-fearful Gage lets Buffy walk him home, while Buffy wonders why Angelus spit the blood out.
The following day, Buffy sits in on swim practice along with Cordy and Willow. The three girls wonder what could be killing off the swimmers. Buffy suspects Gage had steroids in his blood, or something else that might have attracted the monsters. Cordelia comments on a cute new addition to the team, and then realizes that it's Xander. He walks over and informs them that he just made the team. Willow tells Buffy that Jonathan wasn't responsible for the swimmers' deaths, but instead got his revenge by relieving himself in the pool. At the beginning of swim practice, Gage stops in mid-lap to wave and smile at Buffy. Cordelia is delighted that she's dating a member of the Sunnydale swim team, while Buffy and Willow tease him for being almost naked. Later, the team soaks in the sauna. Xander continues to babble, but no one pays attention. Claws come up through a grate, but still no one pays attention.
While Buffy waits for Gage to exit the boys' locker room, she hears him yell. She charges in and finds him with a Gill Monster! Gage suddenly cries out in pain and falls to the ground; he rips open his shirt, followed by his skin, and becomes a Gill Monster himself. As Buffy fights the two monsters off, one grabs her from behind and bites her in the arm. Suddenly, Coach Marin saves Buffy just by bursting into the room; although Marin is alone and unarmed, the Gill Monsters flee. Buffy is sent to Nurse Greenleigh's office. Marin is told that members of his team are becoming Gill Monsters. Buffy and Giles go hunting for Gill Monsters in the sewers, but fail to find any. Meanwhile, Xander again hits the sauna; there he asks where and how he can get some steroids. His fellow swimmers tell him that he's already getting some, right here and now; it turns out the steroids are in the steam from the sauna.
Nurse Greenleigh tries to end Marin's experiments; the Coach has been attempting to improve his swim team's performance, by supplying them with steroids via the sauna-steam. To keep her from exposing him, he drops her through a grate into the sewers; there the Gill Monsters devour her. Xander warns everyone that he's had three exposures to the steam, and is in danger of becoming a Gill Monster himself. Buffy has Giles lock up the rest of the swim team, while she goes to talk with Coach Marin. She confronts him and demands information about the steroids he's been giving them, telling him he'll go to jail. Instead, the coach pulls a gun on Buffy and forces her into the same hole where Nurse Greenleigh was killed. The coach explains to Buffy that, while his monsters have already had their dinner, she's there because "boys have other needs."
Xander and Cordelia help round up the Boys' Swim Team members. Xander enters the locker room to check and see if he's becoming "scaly." A Gill Monster who used to be Shawn emerges from the locker room and jumps in the pool. Cordy, thinking it's Xander, laments about his fate. Xander suddenly reappears beside her, right before "Shawn" attacks Cordy - just missing her. They flee back to the library. Xander decides that, since Buffy hasn't returned, he should go after her. He meets up with Coach Marin and fights him for the gun (which Marin has, for some reason, left on the other side of the room beyond his reach). Xander disarms Marin, who is twice his size, and knocks the coach out. Xander looks down into the hole and sees Buffy, up to her waist in fetid water, surrounded by Gill Monsters who are about to attack and slaughter her. He pulls her out before they can do so. (Note this is the second time - in one and the same episode - that someone has conveniently shown up at the last possible moment to save Buffy, of all people, from certain doom.) Then Coach Marin bashes Xander's head with a pipe wrench from behind, incapacitating but not killing him. Marin then tries to do the same with Buffy, but Buffy ducks and trips him, accidentally causing him to fall into the hole. She tries to catch him, but fails. Being no match for the Gill Monsters in their element, Buffy can only observe as they close in and rip the Coach to pieces...literally biting the hand that feeds them. Xander recovers just in time to join her in witnessing Marin's demise.
The next day, everyone recaps; Xander and the surviving swim team members are given prescribed treatment Giles had the hospital toxicology lab come up with to ensure that the steroids don't take effect. Meanwhile, the Gill Monsters swim out into the ocean.
- Ascended Extra: Danny Strong, previously credited only as "Student," officially becomes "Jonathan" as of this episode.
- Asshole Victim: It's hard to say Coach Marin didn't deserve his fate 100%.
- Attempted Rape:
- A member of the swim team tries this on Buffy. She begins by breaking his nose, but doesn't get much further than that because Snyder shows up, and accuses Buffy of leading him on.
- Marin offers Buffy to be pack-raped by his team of monster fish. When she escapes and he is trapped with them instead...
- Beautiful All Along: Buffy confronts Angelus while drawing out the small stake she was holding her hair bun in place with, Shaking Her Hair Loose in the process. Angelus immediately mocks the trope, saying "Why, Ms. Summers! You're beautiful!"
- This trope could also be applied to Xander. He spends the majority of the series in rather unflattering clothes, and goes undercover ("Not under much" as Buffy says) on the swim team, and Cordelia, Buffy, and Willow are rather stunned to find out that Xander has a good body when in a Speedo.
- Black Comedy Rape: Buffy after being thrown to the fish monsters, fighting them off, then throwing their coach - who threw her in - in with them.Buffy: Great. This is just what my reputation needs: that I did it with the entire swim team.
- Body Horror: The swimmers are turned into fish-monsters, which involves them having to painfully rip off their own skin.
- Breather Episode: Between the Tear Jerker "I Only Have Eyes For You", and the season finale.
- Brick Joke: The Scoobies remember that Jonathan peed in the pool moments before Xander dives into it. Also the Willow Perp Sweating Jonathan gag gets repeated in Season 3's "Earshot".
- Bullying a Dragon: Cameron got off lucky with only a broken nose trying to rape the Slayer.
- Bully Hunter: Buffy saves Jonathan from being forcibly dunked in a bucket of water. Jonathan is not happy at being saved by a girl.
- Could Say It, But...: Principal Synder does not tell Willow to alter Gage's grade just to "look over the number".
- Covert PervertXander: Figure I can keep an eye on Gage and the others when Buffy can't.Willow: Like when you're nude! (Buffy elbows her) I meant to say 'changing.'
- Cowardly Lion: Xander runs like a girl when he first sees the fish monster; he ends up saving Buffy from being raped by a pack of them.
- Cruel and Unusual Death: Nurse Greenleigh eaten alive in gruesome fashion by the swim team.
- Date Rape Averted: It's generally a bad idea to try and put the moves on a Slayer. Trying to coerce or force her however...well the Jerk Jock is lucky Snyder showed up otherwise Buffy wouldn't have stopped with breaking his nose.
- Dissimile:Buffy: So something ripped him open and ate out his insides?Willow: Like an Oreo Cookie. Well, except for, you know, without the chocolatey cookie goodness.
- Eaten Alive: Poor Nurse Greenliegh's fate.
- FaceMonster Turn: The Swim Team guys who become the fish monsters seem to lose any of their personalities and are reduced to a pack of mindless animals.
- Fanservice: Xander wearing nothing but speedos. SMG dripping wet in the sewers showing off some cleavage.
- A Father to His Men: What Marin pretends to be, saying he cares about his boys by feeding them after their transformation. If he gave a damn about them in the first place, he wouldn't have been exposing them to steroids.
- Faux Affably Evil: Marin tries to act like a typical hardass but caring coach. He's actually deeply insane.
- Fishing for Mooks: Angelus tries to sire Gage as a henchvamp.
- Fish People: The Sunnydale High swim team mutates into fish dudes due to their coach giving them illegal, Soviet fish-based steroids. Unusually for monsters in a Buffy episode, they all lived Happily Ever After in the ocean although they did lose their human personalities, so the swim team essentially died.
- Fully-Clothed Nudity: Xander struts into the pool area having secretly joined the swim team, only to be confronted by the female Scoobies staring at him in surprise and some rather frank appreciation. Even though he's already wearing speedoes, a suddenly embarrassed Xander grabs a float board and a tube of lotion to cover the same region.
- Girly Run: Xander when suddenly confronted by the fish-monster.Cordelia: Go ahead. Say it. You ran like a woman. (grins)
Xander: Hey, if you saw this thing, you'd run like a woman, too.
Xander: What about me, what do I do?
- And just a few minutes later,
Cordelia: You could go into the parking lot and practice running like a man.
- Got Me Doing It:Giles: If you're saying these killings aren't random, it would suggest someone's out for revenge.
Buffy: And raise the possibility that someone brought forth this sea monster from whence it came to exact that revenge. 'From whence it came'? I'm spending way too much time around you.
- Grievous Harm with a Body: Angelus escapes Buffy by throwing Gage into her.
- Heel Realization: Nurse Greenleigh comes to see that the experiments she and Coach Marin are doing on the students are wrong after seeing the full effects of the mutations they are undergoing. Unfortunately, Marin remains unconvinced by her pleas.
- Heroine With Bad Publicity: Buffy gripes that she's out breaking her nails fighting the forces of darkness while Jerk Jocks get all the glory. Not to mention her delinquent reputation means everyone takes it for granted she's either Ax-Crazy or Really Gets Around.
- Hoist by His Own Petard: Buffy escapes the rape attempt and the monsters go for the coach instead."Wow...they really love their coach."
- Incredibly Obvious Tail: Buffy following Gage; doomed to failure given she's already drawn attention to herself by roughing up two other members of the swim team.
- Irony: Willow accusing Jonathan of delving into black magic. By Season 6 it will be true for both of them.
- Jerk Jock: Most of the Swim Team. Gage is more of a Jerk with a Heart of Gold, not that it does him any good.
- Karmic Rape + Laser-Guided Karma: The fate of the evil Coach Marin.
- Letting the Air Out of the Band: When the Scoobies realise that the dripping wet, speedo-wearing hunk who just walked in is...Xander?
- Meaningful Name: The coach is called Karl MARIN. (as in MARINe biologist)
- Mistaken Confession:Willow: You hated being pushed around by Dodd and the others. You wanted revenge. Didn't you? (leans in suddenly) (sternly) Didn't you?!
Jonathan: (nervously) Yeah! Okay? I did!
Willow: (with relish) So... You delved into the black arts and conjured up a hellbeast from the ocean's depths to wreak your vengeance.
Jonathan: (confused) What? No! I snuck in yesterday and... peed in the pool.
Willow: (disappointed) Oh. (disgusted) Eww!
- Monster of the Week / Monster of the Aesop: The swimmers turn into monsters for consumming steroids.
- Mr. Fanservice: Nicholas Brendon gets to show off his rather impressive body in a couple scenes. Cordy, Willow, and most of us aren't complaining. Additionally, Gage is portrayed by Wentworth Miller, and gets a few shirtless scenes as well.
- Not-So-Final Confession: When Cordelia thinks Xander has been turned into a fish monster she makes a quite moving speech for someone who is portrayed as shallow and obsessed by appearance.Cordy: It's me, Cordelia? I know you can't answer me, but... God, this is all my fault. You joined the swim team to impress me. You were so courageous. And you looked really hot in those Speedo's. (chuckles) And I want you to know that I still care about you, no matter what you look like. And... and we can still date. Or, or not. I mean... I understand if you wanna see other fish. I'll do everything I can to make your quality of life better. Whether that means little bath toys or whatever.Xander: (walking up behind her) Uh, Cordy? That's not me.
- Night Swim = Death: Ultimately averted: it wasn't a monster killing a swimmer, it was the swimmer who became a monster.
- Perp Sweating: Mild and geeky Willow enjoys interrogating Jonathan (with desk lamp) when the Scoobies suspect him of murder. The gag is repeated again in "Earshot".Willow: The trick is not to leave any marks.
- Rape Discretion Shot: After the coach ends up in the tank with the fish monsters instead of Buffy, the camera cuts to Buffy and Xander's reactions.Buffy: Wow. They really love their coach.
- Rescue Romance: The previously sullen Gage is quite taken with Buffy after she saves him from Angelus.
- Rushed Inverted Reading: Buffy attempts to watch over Gage. When he turns around to look at her, she looks back at her upside magazine.
- Save the Day, Turn Away: A rare aversion where, after saving Gage, Buffy does something she's almost never done in the series and walks him home.
- Self-Disposing Villain: While trying to kill Buffy, Marin falls into the pit he's been keeping his fish monsters in.
- Shirtless Scene: Holy crap, Xander.
- Shout-Out: Cordelia thinks Xander will get turned into the creature from The Blue Lagoon. He corrects her by saying it's Creature from the Black Lagoon.
- Show Some Leg: Buffy tries to convince Gage she's a swim groupie, but lacks Cordelia's ability to carry off Blatant Lies.
- Skewed Priorities: Cordelia as per usual. When she finds out that two members of the swim team are dead, she worries about the state championship. Later, when Xander is about to be turned into a monster, she's more worried about dating a monster
- Played for Drama: The Coach believes it's important to win...even if this means continually exposing teenagers to a steroid gas that transforms them into vicious, mindless beasts.
Marin: What kind of question is that? For the win! To make my team the best they could be! Do you understand we have a shot at the state championship?
Buffy: Do you understand that I don't care? It's over! There's not gonna be any swim team.
Marin: Boy, when they were handing out school spirit, you didn't even stand in line, did you?
Buffy: No. I was in the line for shred of sanity.
- Slut-Shaming: Combined with Victim Blaming. Cameron and Coach Marin blame Buffy's attempted rape on her "leading him on" and wearing sexy clothes. When facing possible gang rape by fish monsters, she makes a comment about what that will do to her damaged reputation in school.
- Soviet Superscience: The formula the Coach and Nurse Greenleigh use to strengthen the swim-team and turn them into fish monsters is apparently based on Soviet experiments done on the Olympic swim-team that came to light after the end of the Cold War.
- Space Whale Aesop: Steroid abuse leads to becoming a fish-monster. Trying to rape the Slayer will lead to either your nose being broken or you'll be torn apart by fish monsters.
- Take My Hand: Xander to Buffy. Buffy also shouts this to Couch Marin but it's too late.
- Team Spirit: Apparently involves steroid abuse and alteration of school grades.
- Token Good Teammate: Gage is much nicer than the rest of the Swim Team, and even has a bit of Ship Tease with Buffy. It doesn't help him.
- Too Spicy for Yog-Sothoth: Angelus tries to sire one of the swim team as a henchvamp for his upcoming fight against Buffy. He doesn't like the taste.
- Very Special Episode: The swim team is given a drug which is constantly referred to as a steroid but ends up turning them into fish.
- Villain: Exit, Stage Left: Angelus flees yet again after Buffy rescues Gage from him.
- We Will Meet Again: A heroic version with Buffy saying "This isn't over" when Coach Marin forces her into the grotto at gunpoint.
- You Have Outlived Your Usefulness: When Nurse Greenleigh tells Coach Marin of her concerns, he gleefully pushes her into a pool with his boys. She's subsequently eaten.