Katie Burke, portrayed by Katie Holmes, is a graduate student who finds herself overwhelmed by the pressures of academic life. One day, her friend Sam, played by Zooey Deschanel, convinces her to attend a job fair, where a charming recruiter takes a particular interest in her. However, Katie's mind is preoccupied with completing her thesis and a haunting past.
Meanwhile, Detective Wade Handler, characterized by Benjamin Bratt, an ex-alcoholic, is assigned to investigate a missing persons case linked to Embry Larkin, played by Charlie Hunnam, a wealthy orphan who vanished two years ago. It turns out that Embry was Katie's boyfriend, and he disappeared under mysterious circumstances. Initially, Katie is unsure if he left voluntarily or if something more sinister occurred.
In an attempt to distract herself from her academic stress, Katie joins Sam and their friends August and Amanda at a party, where things take a turn when she believes she spots Embry among the crowd. The situation escalates when Handler uncovers unsettling evidence suggesting Embry's potential demise, such as unused tickets for a trip that he purchased before his disappearance.
As Katie immerses herself in her studies, a curious incident occurs; she finds a number etched into her desk leading her to a chilling encounter in the library, where she senses Embry's presence. This haunting connection deepens as Handler conducts interviews with Katie's friends, revealing tension surrounding her relationships.
After a string of bizarre events, including the discovery of Embry's eyes staring at her from a library shelf, Katie's mental state begins to fracture. A peculiar girl named Mousy Julie brings unsettling news about Harrison, another friend, prompting Katie to confront Embry at his secluded cabin.
What seems like a confrontation with her past quickly spirals into chaos. Katie’s struggle with her emotions manifests in violence, leading to a series of shocking events, including her clash with Handler. As realities intertwine, flashbacks of a turbulent relationship reveal disturbing truths about Katie’s psyche.
In a gripping turn of events, Handler comprehends Katie's unstable condition and the twisted reality she has created in her mind. The story takes a dark turn as Katie resorts to deadly measures to protect her secrets, resulting in Handler's tragic fate.
The narrative concludes on graduation day, where the group of friends reconnects, but Harrison's disappearance and the lingering shadows of Handler's fate weigh heavily on Katie. An epilogue showcases Katie's return to the work environment she desired, hinting that her dark tendencies might resurface, leaving audiences questioning if the past truly ever stays buried.
