Allison is first introduced in the beginning, stepping out of a gray sedan. She goes to the front window, as if to look in, but the car drives by her. She then begins walking to the school. Allison is the last out of the Breakfast Club members to enter the library. She heads all the way to the back, and faces the opposite direction. When Principal Vernon when walks in, for the most part, she ignores him. When he sets the paper down in front of her, she just glares at him, yet says nothing. When Principal Vernon leaves, Allison barely notices. Allison begins chewing on her nails loudly, and all of them turn to watch her. Bender makes a snarky comment on how if she eats her hand, she won't be hungry for lunch. She responds by spitting the nail at him. He then replies, "I've seen you before, ya know." When Bender and all of them are talking/arguing, Allison is the only one not to join in on the first conversation. She smiles slightly when Brian makes the comment of Andy wearing tights for wrestling. Once Bender takes the screw out of the door, she's also watching him with the others. Principal Vernon walks in once more, interrogating them about why it's closed. When he asks 'Who closed that door?' again, Allison squeals and bangs her head against the desk, making squealing noises. Bender reveals that she doesn't talk. Once Principal Vernon leaves, she lifts her hood slightly to see what he was trying.
When the door is closed, Allison passes the time first by wrapping a string around her index finger, to make the tip purple. She then passes it by drawing a picture of a bridge with her pen. She works on it and appears to be a good artist. She then begans scratching her head wildly, so her dandruff would fall on the paper to make it look like it was snowing. Allison slowly rests her head on her hands, carefully bringing her head down until it touches them, watching the others with blood-shot eyes. She then closes her eyes and falls asleep.
Allison, along with the others, raises her hand when Principal Vernon asks who needs to use the lavatory.
Claire is complaining about how her parents just use her to get back at each other. Once she says this, Allison says her first words in the movie, screaming "HA!" They all look at her, shocked [Andy smirking slightly]. She has her chin raised, hair wild, and gives Claire a smile. Claire just tells her to shut up. After Bender sticks his knife into the chair next to her, she reaches over and grabs it, stealing it.
After they all begin whistling, Allison joins in for once slight part, before quickly shutting her mouth. She is picked along with Andy to get the soft drinks in the teachers lounge. Principal Vernon keeps snapping at her to get up, in which she does and slings her bag across her shoulder.
When walking with Andy to get the drinks, he asks what's her poison. She doesn't respond, and once he gives up, she replies with "Vodka." He then asks when she drinks, and she answers "Whenever." At his last question, "How much?" She says "Tons". Andy asks her if that's why she's here today, and she says no. He then states why is she, and she retorts "Why are you?" They glare before Andy replies how his father and wrestling coach believe it'd be good for him. She doesn't believe him, telling him to tell her why he's really in here. He says forget it, and the two return to silence.
Bender chucks her a Cola, and without even looking, she catches it. She appears to be staring the back of an album sleeve. When opening her lunch, she distaintfully throws the meat over her shoulder, in which it lands on the statue. She then takes two sugar packets and sprinkles them across the two pieces of bread, now and then going and gulping in the falling sugar. Once done with them, she sticks both of them into her coke. She then preceeds to place cereal on the sandwich, pounding it in. The others now watch her, and she brings up her sandwich, biting into it. She notices the others staring, but ignores them. After Bender climbs up the stairs, she watches him, before returning to staring at Andy, Brian, and Claire.
Allison follows the others outside the library. She is calmly walking behind them all. Once Bender gets his weed, Brian blinks at her, clearly shocked. He asks her "Do you approve of this?" Before he walks after them. Allison then quickly steals Bender's lock.
When all of them first begin running, she stays standing, only to follow them after they go in the other direction. She appears to agree with Bender when he says they have to go to the cafeteria, and waits for him, stomping backwards as the two then reluctantly follow the others.
Allison also begins making noises to protect Bender from getting caught by Principal Vernon. She is also the only one not to go smoke when Bender gets his weed from Brian's pants. She watches as Andy soon follows the others, realizing he does everything everbody else does. Allison just seems upset when she hears the glass shattering.
Allison answers Brian's question when he asks Andy if he knows what his middle name is. She also states his height, weight, and security code. When Andy asks how she knows all this, she states how she stole his wallet. Allison chucks it at him after he demands it back. When Brian calls her a thief, she says how she's not. She says how there's nothing to steal but two bucks and a nudity picture. She calls it peverted, and seems disgruntled by it.
Allison asks if they want to see what's in her bag, and when they both say no, she seems upset, but soon dumps it out anyway. She has clothes, tampons, and other various objects in the bag, as well as a comb. When they ask if she always carries this around, Allison says they never know when she might need to break. She could run away to the ocean, mountains, Africa, and Afghanastan. She calls her home-life 'un-satisfying', and when Brian tells Andy to get in on this, Andy says everyone's homelife is unsatisfying. Brian whispers to Andy how hers might go a bit more beyond theirs. Allison snaps for them to forget it and 'There's no deal sport-o'. Andy challenges she either carries that much crap around in her back because she is actually considering running away, or she wants others to believe she is. She then gets up and says hotly, 'Eat shit' to Andy. Andy soon gets up to follow her.
Allison is doubled over on a desk full of books, crying silently. When Andy asks if she wants to talk, she tells him to go away. When Andy begins to walk away, she tells him, "You have problems!" He replies with, "Oh, I have problems!" She replies by telling him he does what everyone elses does and asks him too, making that a problem. Andy responds with at least he didn't dump it out on a couch and share it with others. In a much softer, kinder tone, Andy then asks what's wrong. Andy keeps saying, "Is it bad? Real bad?" He then says, "Parents?" Allison, with tears in her eyes, says "Yeah". He asks what they do, and after a moment of hesitation, she says "They ignore me." The scene ends with Andy nodding, repeating "Yeah."
Allison is sitting between two chairs. When Andy is done speaking, Allison says how she'd do anything sexual, and she wouldn't need to be paid. Claire rolls her eyes, stating she's lying. She also remarks how she's done a lot of sexual things except for the illegal stuff, calling herself a nymphomaniac. She told her shrink this, and after Andy asks what'd he do once you said it, she says, "He nailed me". She says it wasn't considered rape since she paid him. She also says how after the first few times, but is interrupted by Claire. Claire is digusted by her, and Allison asks if Claire ever did it. She compares it to a "double-edged sword". If she says no, she's clear, and if she says yes she's a slut. Allison then later comments, "Or maybe she's a tease". This manages to get Claire to admit she's a virgin. Allison then replies how she's never done it either, for she is a compulsive liar. Claire calles her a bitch, and how she tricked her. Andy defends her, saying how Claire's just upset because Allison got her to admit something she didn't want to. Allison abruptly says how she would do it, since it's ok if you love that person. Allison also answers for Andy when Claire asks what's his problem. She states how he cannot think for himself. Andy agrees, explaining why he got in there. Allison watches him with sympathy in her eyes when he exclaims how he hates his father.
Allison breaks the silence after feeling left out, saying how she can write with her toes, and can also eat and brush her teeth. She also pours her heart and soul into the piano. Allison also defends Claire when Bender mocks her, saying how he promised he wouldn't laugh. Allison remarks how when people grow up, their 'heart dies'. When Bender says who cares, she replies, "I care." She appears to be on the verge of tears. She then asks Claire what would she do if she walked up to her, and Claire replies, "The same exact thing." Bender defends Allison by shouting at Claire, "YOU ARE A BITCH!" Allison then replies at how growing up to be their parents is 'inevitable'.
Allison reveals how she got into detention. She did nothing, for she 'didn't have anything better to do'. When they all laugh, she joins in.
Allison is first dancing with the statue, before going off to throw each fist up and down. Allison is tossing her hands like the backstroke at one point while dancing. Her and Bender are then ontop of a desk, moving in the same direction while sliding with their feet. Her and Claire are then both shaking on the desk. The dancing scene ends with Allison ducking lower to the ground, until she just huddles there, not moving.
Allison nods her head along with Andy, giving permission to Brian to write the letter from all of them. Allison is taken away by Claire, who gives her a makeover. She puts a headband in her hair to pull it from her eyes, revealing her face. She also puts eyeliner on and gets rid of the black 'shit' under her eyes. When Allison walks out of the room, Andy looks at her in awe. She is wearing a white-pink dress, and when Brian mouths 'cool!', she gives him a smile and responds with a thanks. When Andy asks her what happend, she says, "Why? Claire did it!" Andy says how she looks different, and how he can see her face. Allison asks if that's a good or bad thing, and Andy responds with 'Good'. The scene ends with both of them smiling at each other.
Allison walks down the hall with Andy when they all leave, and outside, has his blue sweatshirt around her shoulders. Andy pulls her into a kiss, and the two kiss, until they pull apart. Andy is dumbstruck, watching her, and she rips a patch off from his jacket. He continues to stand there, watching her, slightly pulling on her as she backs away to her car, still watching him. You can see Andy turn when he gets into his car to watch Allison. Allison, in the letter, says, "And a basket-case."