Twenty-five years ago, Lauren Phelps and her sister Patty were kidnapped from their backyard on Long Island. Lauren escaped her captor, but Patty was killed.

Ever since, Lauren has suffered from nightmares of the "Shadow Man." Trying to recall his face and avenge her sister's murder, Lauren, now a kidnapping investigator, enrolls in a clinical trial for a new memory drug.

At the offices of Memory Makers in California, she receives the injections of the Memory Makers' serum, and begins to experience flashbacks of repressed memories. Along with the flashbacks, she receives threats from an anonymous source that point back to her childhood trauma.

Soon, Lauren becomes involved with a fellow trial participant who seeks to recall his own traumatic past. But can Lauren discover the identity of the "Shadow Man" before history repeats itself?