Mona Gray (Jessica Alba) systematically withdraws from life into a world of mathematics after a mysterious mental illness leaves her father (John Shea) incapacitated and a shell of his former self. Forced by her mother to move out on her own, Mona gets a job as a math teacher at an elementary school. There she discovers she has an unorthodox talent for teaching and finds herself thrust back into life again, with children to care for, and a reason to live. Mona takes special interest in one of her students, Lisa Venus (Sophie Nyweide), whose mother is dying of cancer.