Three girls, Frankie, Tabby, and Lourdes, try to freeze time with magic, but fail to do so as they require a fourth member. Lily Schechner moves into the town with her therapist mother, Helen, to live with Helen’s boyfriend Adam Harrison and his three sons, Jacob, Isaiah, and Abe. The girls befriend Lily after she has her period in class and is mocked by her other classmates, especially Timmy. They are amazed when she telekinetically pushes Timmy into the lockers. When Lily responds to them using only her mind, the girls confirm her to be their fourth member and invite her to join their coven, to which she agrees. As a result, they succeed in freezing time.
To seek revenge on Timmy, the girls cast a spell on him. The next day, Timmy behaves sensitively, confirming the girls’ success. They continue to experiment with their powers, including levitation. When Adam discovers about the incident in school, he scolds Lily but Helen defends her. Lily overhears them arguing and goes outside where Abe talks to her about his father’s authoritarian beliefs. Timmy hosts a party, inviting the coven, and apologizes to Lily, eventually becoming friends with the coven. When Timmy is at Lily’s home for a project with Jacob, he admits to the girls that he had sex with Isaiah, Jacob’s elder brother, and that he is bisexual. Later, Lily places a love spell on Timmy, using his sweatshirt, and the two kiss.
The next morning, during class, the coven is told by their teacher that Timmy allegedly committed suicide the night before. Lily opens up to her friends about her kiss and love spell. They sever ties with her and bind themselves from magic. Lily suspects Adam to be dangerous and asks her mother for them to move out, but she does not agree. In hopes to find anything against Adam, she searches his office only to find her own adoption papers while Helen admits to her that Lily is actually her patient’s child. After Timmy’s funeral, Helen tells Lily she agrees to move out. She also admits that she knows about her powers and asks her to give her powers to her. When Lily suspects her, Helen shapeshifts and turns out to be a disguise by Adam, who, being part of a pagan cult, has been after her powers since the beginning and knocks her unconscious.
Lily awakens in a forest at night with Adam, who confesses that he murdered Timmy and threatens to kill her too. When Timmy contacts Lily’s friends and tells them about his murder through a Ouija board, they arrive to save Lily by freezing time, but Adam subdues them quickly. The girls then work together and use their elemental powers to defeat Adam, burning him to death. Later, Lily continues her friendship with the girls and Helen takes her to an asylum to meet her birth mother, who is revealed to be Nancy Downs.