In 1986, cult actress Susan Cabot is found dead in her Los Angeles home; suspicion immediately falls on her son, Timothy Roman, the only witness and immediate suspect; what begins as a shocking Hollywood murder soon opens into a darker story.

The investigation deepens and Timothy's story becomes more complex; Timothy's life was shaped not only by his mother's troubled past but by a chapter in American medical history, as a patient enrolled in a now-buried clinical experiment.

Susan's body is discovered in her bedroom, bloodied, broken and surrounded by confusion; Timothy offers a surreal account of masked intruders, but his story unravels quickly; under pressure, he admits the truth.