In New York City, Thana, a mute young woman, leaves her job in the Garment District, where she is pulled into an alley and raped by a masked attacker. Later, Thana arrives home to discover a burglar ransacking her apartment. The armed intruder also rapes Thana, but drops his .45 caliber gun during the assault. Thana hits her attacker with a paper weight and knocks him unconscious, then smashes an iron into his head, and drags the body into her bathtub. The traumatized woman huddles in her living room and stares at the burglar’s gun. The next day at work, Thana’s boss, Albert, and her co-workers notice she is more withdrawn than usual. As the janitor changes the trash can liners, Thana’s attention is drawn to the dark green garbage bags. Later, Thana cuts the burglar’s body into pieces, wraps them in garbage bags, and stores the body parts in her refrigerator. After scrubbing the blood from her tub, Thana hallucinates another attack. When she leaves carrying a green garbage bag, she meets the landlady, Mrs. Nasone, with her dog, Phil, in the hallway. Nosy Mrs. Nasone offers to take out the trash, but Thana leaves with the bag and drops it in a street trash can. At work, Thana continues to be distracted and burns a silk blouse. Later, a man heckling women from his street corner notices Thana get out of a taxicab and follows her. Thana carries a shopping bag containing a green garbage bag and drops it in an alley. The heckler picks up the bag and chases her to return it. Thana panics and runs, but gets stuck in a dead-end alley. She pulls the burglar’s gun from her purse and shoots the heckler. When Thana returns home, Phil runs into her apartment and starts sniffing at the refrigerator, but Mrs. Nasone shoos her dog away. That night, Thana is plagued by nightmares. At work, Albert chides Thana for her recent poor performance, reminding her that she must work hard to compensate for being mute. As Albert places his hands on her shoulders and invites her to a Halloween party, Thana is uncomfortable and moves away, but writes a note promising to try harder. At lunch with her co-workers, the friends laugh at a couple kissing passionately at another table. When the man’s date leaves, he flirts with Thana’s group, but is laughed off. When Thana remains at the restaurant to wait for her friends’ change and then exits the restaurant, the man joins her, claims to be a photographer, and invites her to his studio for a photography session. Thana follows the photographer inside, shoots him several times, and leaves. She returns home, dresses provocatively, puts on heavy makeup, and leaves with another garbage bag. Thana deposits the bag in an airport locker, then roams city streets. She comes upon a pimp beating a prostitute, and riddles him with bullets. In Central Park, she attracts the attention of a gang. As five gang members surround her, Thana pulls out her gun and kills them. When she leaves the park, a limousine pulls up and the driver opens the door for her. The rich Arab in the back seat offers Thana money to go with him. She pockets the cash, then kills the Arab and the driver at the next stop light. At home, she washes blood from her hands and hears Phil barking loudly. Thana removes a body part from her refrigerator, grinds it, and brings the meat to Mrs. Nasone’s apartment, where Phil gobbles the food. Later, Mrs. Nasone watches as Thana leaves with more garbage bags. On another street, Thana passes a man loading luggage into his car trunk and when he rushes inside for more luggage, she tosses a garbage bag into his trunk. At work, Albert scolds Thana for not returning after lunch on Friday. He is also upset because it is rumored she is not going to the Halloween party, but Thana hands her boss a note, stating she wants to attend. He asks if she will go with him and she agrees. That night in Chinatown, Thana observes a couple kissing. As the girl returns to her sales job, Thana follows the man, but he enters his apartment building before she can catch him. At a bar, she meets a man who complains about his cheating former wife. As he and Thana walk to a park bench by the river, the man reveals his knowledge that his ex-wife was sleeping with another woman and, in retaliation, he strangled her cat. Thana retrieves her gun, but it does not fire. The man grabs the weapon, asking if it is a fake. When he points it at her, she recoils, but he then aims the gun at his head and unwittingly kills himself. Later, at her apartment, Thana hears Phil barking outside as she places one of the garbage bags in her closet and sneaks out the fire escape with more bags. Mrs. Nasone lets herself into Thana’s apartment and looks around, but as she opens the closet, Phil knocks over a vase, resulting in a stain on the rug. Mrs. Nasone rushes out, scolding Phil that the stain will reveal their presence in Thana’s apartment. The next day at work, Albert lets everyone leave early to prepare for the party. Thana returns home, stares at the stain on her rug, and writes a note offering to take Phil for a walk. Mrs. Nasone is reluctant, but allows Thana to take her dog. She drags the animal to a deserted area by the water, ties him to a post, and takes out her gun. Later, Thana leaves a note for Mrs. Nasone that Phil came off his leash and disappeared. Thana kisses each bullet as she loads her gun, then puts on heavy makeup, dresses as a sexy nun, and goes with Albert to the Halloween party, where she joins her co-workers. Meanwhile, Mrs. Nasone, fearing that Thana killed Phil, sneaks into Thana’s apartment. She discovers the bag in the closet, is shocked to find the burglar’s severed head inside, and calls the police. At the party, Thana dances with Albert, then allows him to take her upstairs. As Albert lifts Thana’s dress, he discovers the gun tucked into her stocking, and she shoots him dead. Thana returns downstairs and continues to kill men. Behind her, a co-worker grabs a cake knife and stabs Thana in the back. She turns and aims her gun, but does not shoot the woman. Thana dies and, elsewhere, Phil returns home, alive.