Sam Montgomery is a high school senior who lives with her stepmother and stepsisters after her father's death. She is not only unpopular and constantly bullied at school but also treated poorly at home. Despite this, she has a passion for writing and dreams of going to Princeton University.
Sam finds solace in her online conversations with Nomad, who she believes is her soulmate. They share their interests, fears, and dreams, but neither knows each other's real identity. Nomad invites her to meet him at the Halloween dance, and Sam feels nervous but excited about the prospect of finally meeting him.
However, her stepmother forbids her from going to the dance, but her friend Carter convinces her to sneak out and attend anyways. Sam wears a masquerade mask and meets Nomad in the middle of the dance floor. They hit it off and have a great time together, but Sam realizes she has to leave before midnight to avoid getting caught by her wicked stepfamily.
During the night, Sam drops her phone, which her stepsister finds and reads her text messages with Nomad. The next day, rumors about their secret relationship spread around the school, and Sam becomes even more of a target for bullying. The stepsister also informs Sam's stepmother about her going to the dance, and she is punished severely.
Determined to meet Nomad again, Sam tries to figure out his identity using the clues they've shared. Meanwhile, Sam's stepsister Shelby is crowned homecoming queen, and Sam is forced to be her slave for the night. During the event, Sam discovers that Nomad is Austin Ames, the popular quarterback she's not supposed to get along with.
Sam and Austin finally come clean about their feelings for each other, and Sam's stepmother gets exposed for stealing money from the diner's account. In the end, Sam's dream of going to Princeton comes true, and she and Austin become a couple.