A researcher investigating a notorious serial killer who was hanged 20 years earlier seemingly becomes possessed by the long dead strangler. A researcher investigating a notorious serial killer who was hanged 20 years earlier seemingly becomes possessed by the long dead strangler. A researcher investigating a notorious serial killer who was hanged 20 years earlier seemingly becomes possessed by the long dead strangler. A researcher investigating a notorious serial killer who was hanged 20 years earlier seemingly becomes possessed by the long dead strangler.