The clock is about to strike 12. A young ad exec named Val Butler fears for her life. Once midnight arrives, she believes she's going to die. The lights in her apartment flicker. Val calls 911. She screams. It's 12 o'clock. Just as she'd feared, Val is now dead. Castle notices the apartment shows no sign of a break-in, or a break-out. The victim's face bears a look of sheer terror. It's as if she got scared to death.
Val's roommate, Amanda, says the victim had been acting paranoid for the past three days. Castle notices the apartment is filled with items used to ward off evil spirits. Should they be looking for someone who did the killing or something? Val's bad news ex-boyfriend, Freddie Baker, says she accused him of sending her a package. It contained DVD. Castle watches the video. It's filled with disturbing images as well as an unsettling message. A voice says, "Midnight on the third day, you die." Castle believes Val was killed because she watched the DVD. Now he's seen it, too. That can only mean he's next.
Castle's freaking about suffering a fate similar to those victims in the movie The Ring. Beckett isn't a believer. She watches the DVD without fear, but does admit that it's pretty creepy. The symbols that are seen represent rebirth and resurrection as if something that has come back from beyond the grave. A man named Jason Bennett in Jersey also received a copy of the DVD. Indications are that he also died three days after watching it. Beckett wonders what the connection is between the two victims.
Castle forgoes Beckett's tempting offer to spend the night together. In every horror movie he's ever seen, having sex leads to death. Well, that's true. Castle spends a sleepless night worrying about his fate. He calls the one man who may know how he get out of this real-life horror story-scare-master extraordinaire Wes Craven. The man behind classic scary stories like A Nightmare on Elm Street and Scream provides some helpful advice. Castle realizes that one of the images on the DVD is of a real hotel called the Brunswick Inn. Both victims stayed at the place in November of 2008.
The two murder victims were staying at the Brunswick Inn while testifying in a trial for a notorious serial killer named Nigel Malloy. Beckett believes the killer must be taking vengeance on those who testified against him. The only problem with that theory is that Nigel Malloy is dead. An interview that was recorded just before his demise has Malloy saying his spirit would always live on. His brother, Leopold Malloy, may be pulling strings on his dead sibling's behalf from his home in an asylum. The nurse lets Castle and Beckett question Leopold, but the creepy little inmate vows he wouldn't ever jeopardize his appeal.
Ryan learns that Nigel Malloy's body is missing from his grave. The team believes a third witness in the murder trial, Mark Heller, may be the next target. He received a DVD in the mail a few days ago. Beckett drags Castle to the place where Heller is hiding. It happens to be an isolated cabin in the woods where there's no cell reception. Classic horror movie stuff. Good thing Castle brought a bottle of holy water with him. Before they lost all cell phone reception, Ryan and Esposito were trying to tell Castle and Beckett that this case may not be what it seems.
Mark Heller is sitting scared in a chair when Castle and Beckett arrive at his place. Midnight is just around the corner. A mystery figure is seen lurking in the woods as the lights go out in the cabin. Beckett heads outside to investigate. She tackles the mystery figure only to see that it is Leopold's nurse. She's not the killer. She came to save Heller at Leopold's request because she loves him. She needs to stop the murders so Leopold wouldn't be to blame. The nurse is the one who dug up the grave. Like Castle, she also fears the dead killer's spirit has come back to strike again.
Mark Heller tells Castle that the cops initially arrested the wrong man in the serial killer case. He says that the police pressured him and the other two witnesses to ID this innocent man in a lineup. The first suspect couldn't take the false accusations. He electrocuted himself in his cell. He died at midnight on the third day he was in prison. The man had a daughter. Her name is Amanda, just like Val's roommate. She's one who has been killing the witnesses who identified her dad. She's about to kill Heller until Castle whacks her over the head with the bottle of holy water. It really does ward off evil. Case closed.
Back when Castle was worried about death at the hands of evil spirits, he was desperately trying to knock things off his bucket list. Beckett is pleasantly surprised to see that "Be with Kate" was at the top of the list. She tempts Castle into helping her cross something off her bucket list. It takes place in the bedroom and involves ice. Castle believes this is definitely something worth living for. Still, he wants to wait until after midnight on this third day. Okay, sex only kills in horror movies, but why tempt fate?