Julie Swanson is a single, hardworking professor, admired by her University of Minnesota students. She awakes in a hospital following a brutal beating and begins to experience strange déjà vu-like sensations. She seeks answers from renown neuroscientist Karl Undset who compares her unusual episodes to a well-established scientific condition known as dual processing. Her injury has resulted in a new ability to sense elevated autonomic indicators present in certain voice patterns, those that change under stress. She’s processing these indicators in the same way a polygraph detects elevated levels of blood pressure, skin conductivity, and heart rate. Julie, in effect, has become a lie detector. She and her brain surgeon become romantically involved and together they devise a plan to use her ‘sixth sense’ to find her attacker.