What the Night Knows

by Dean Koontz

The novel begins with John Calvino investigating the murder of a family, committed by Billy Lucas. Billy is in a mental institution and being monitored for being schizophrenic. He openly admits to having killed his family and can describe to John in graphic detail how he murdered them. John goes to visit Billy; Billy indicates that the reason he killed them was because of “Ruin”. As John is leaving, Billy's countenance changes and he begins saying “help me”.

John begins to investigate the murders, and finds that there are a number of similarities between the murders committed by Billy, and murders committed by Alton Turner Blackwood some 20 years previously. Alton Blackwood killed John's entire family. The two families were murdered in almost exactly the same way.

John's family (his wife Nicolette, and his children Zach, Naomi, and Minette), begin to be haunted by dreams, sounds in the house, and ghostly phone calls. John receives a call from Billy taunting him and saying things that only John or Alton Blackwood would know concerning John's sister. John follows up on Billy to find out he does not have a phone in his cell and could not possibly have made the phone call.

John begins to work on the theory that it wasn't Billy Lucas that killed his family, but rather Alton Blackwood.

Billy is found dead in his cell having died from the stress of what he was going through.

John's wife Nicolette, who had oral surgery three months before, begins to be haunted. Thinking that the medicine she received for her teeth were causing hallucinations, she sees he doctor again, only to have him confirm that the Vicodin she took at the time has not had any adverse effect.

The reader begins to learn about other instances of people being possessed by the spirit of Alton Blackwood, known as the “rider”. A man named Reese Salsetto, possessed by Alton, attempts to kill his sister Brenda's family and rape his niece. Brenda shoots Reese dead; Alton then tries to possess her. In the fight, in order to escape Alton, she turns the gun on herself. It is later learned that she was trying to fend off the spirit trying to possess her. The spirit of Blackwood enters many others and causes them to do deplorable crimes.

John believes that the spirit of Alton Blackwood is possessing people. He tells another detective, his friend Lionel, who is tentative but believes him. He goes and talks with a friend, Priest Abelard, who tells him about possession but who is not willing to help due to his own personal demons.

John's daughter Naomi begins meeting with Melody Lane, a possessed woman who claims to be a fairy queen from a fantasy land. They develop a friendship.

Alton Blackwood has killed on a 33-day cycle. John believes that on the next cycle he will try to kill John's family; however, the spirit advances the timetable and attacks early. Numerous people are possessed including the drug-addicted son of Calvino's housekeepers, child-killer Melody Lane, reporter Roger Hodd, and the children's math tutor, Professor Sinyavski. All four attack John's family in their house. John's family fights against the possessed people.

The book ends with John offering his own body to the spirit, and with his youngest daughter's mysterious aid is able to defeat Blackwood's spirit and shed the less literal demons that have been haunting him since the murder of his first family.