The secretary Liza Raines becomes deaf after a shooting in a robbery, is evicted and later she is found by the social assistant Grant Kane living in her car. Grant brings Liza to a Transition Shelter to be rehabilitated, and she accepts to be submitted to an experimental treatment never tested in humans in the Center for Hearing Research. The leader of the research Dr. Gene Kramer is pressed by the CIA agent Aiden Porter that is funding his experiment to test his vaccine of restoration of cells in fifteen patients, and he advises that the rats subjected to the experiment became psychotic. The patients also become psychotic and suicidal, with the exception of Liza, the patient 14. She achieves the ability of hearing frequencies emitted by the brain and read minds as a side effect. Porter recruits Liza to work in CIA disclosing the innermost thoughts of the suspects, but later Liza finds his real hidden intentions.