Authorities are baffled by Longlegs, a satanic serial killer who never once touches his victims. All of his crimes over the years seem to be straightforward murders and suicides, in which a husband and father murder his family before taking his own life. At each crime scene, however, Longlegs (Nicolas Cage) leaves a letter written in code, making it clear that more murders are to come. To help crack the horrific case, the FBI calls in rookie agent Lee Harker (Maika Monroe), who is gifted with psychic abilities. The case is full of unexpected twists and turns, including references to the occult. Lee discovers a personal connection to a ruthless killer and must race against time to stop him before he takes the life of another innocent family.