Nicole Walker, a naive teenager, is living with her father Steven, stepmother Laura, and younger brother Toby in Seattle. Seeking excitement and escape from her family's watchful eyes, Nicole meets David, a charismatic and mysterious young man. Despite her father's warnings and concerns, Nicole is drawn to David's charm and begins a passionate romance with him. At first, David appears as the perfect boyfriend—attentive, affectionate, and protective. Nicole is enthralled by the intensity of their relationship, which offers an exhilarating contrast to her sheltered upbringing.

However, cracks in David's facade soon begin to surface. Steven becomes increasingly wary of David's intentions when he notices odd and menacing behaviors. His concern grows as he discovers unsettling details about David's past. Ignoring his distrust for David, Nicole initially resents her father's interference in her personal life. But the situation escalates as David's obsessive and violent tendencies become unmistakable. Tensions rise as Nicole finds herself caught between her infatuation with David and the alarming reality of who David truly is. As her father's attempts to protect his family intensify, impending danger looms over Nicole and her loved ones. The boundary between love and obsession becomes terrifyingly blurred as the façade of David's charm gives way to darker impulses.