Maggie O'Connor (KIM BASINGER) is a single nurse who works in a New York-based psychiatric hospital. Her well-ordered life is suddenly disrupted when her estranged sister, Jenna (ANGELA BETTIS), a heroin addict, unexpectedly drops by and then leaves her week-old infant girl there. Not knowing what else to do, Maggie raises the girl as her own, loving her like the daughter she never had, despite the girl presumably suffering from autism, a mistaken diagnosis for her supernatural powers.
Six years later, Cody (HOLLISTON COLEMAN) is a happy little girl still living with Maggie and attending a special Catholic school where Sister Rosa (LUMI CAVAZOS) and the other nuns tend to their class of mentally challenged youngsters. Despite their challenges, those kids are luckier than the ones who've been murdered in what appears to be a serial killing spree that's drawn in special FBI agent John Travis (JIMMY SMITS). A former seminary student and current specialist in ritual homicides, Travis believes a cult of devil worshippers is responsible for the deaths.
At first that has nothing to do with Maggie and Cody, but when the former meets Cheri Post (CHRISTINA RICCI), a teenage junkie who knows of Cody's special gifts and warns that's what "they" want the girl for, Maggie becomes concerned. Her fears are then realized when Jenna suddenly shows up with her new husband, Eric Stark (RUFUS SEWELL), the founder of The New Dawn, a highly profitable self-help organization, and abducts the girl.
It gets worse when Travis informs Maggie that Stark's organization is really a front for a network of devil worshippers who are searching for a child born on a certain date and predestined to lead the masses to God. Realizing the supremacy he could attain by converting such a power from good to evil, Stark believes he's found the chosen child in Cody and sets out to shatter her belief in God. Realizing that Stark will kill Cody if he can't convert her and her powers to evil before Easter Day, Maggie and Travis race to find Cody and Stark and stop the madman before he does either.