Haunted is a novel by author Meg Cabot, and is fifth in the series of the Haunted novels. In this novel, Susannah, is a 16 year-old girl who is also a mediator. As a mediator, Susannah talks with ghosts to help them resolve the issues they had when they were alive so they can pass on to their next life. Susannah takes readers into the lives of her family and the other people living in the town of Carmel, California.

As the story unfolds, the readers learn about the many situations in whic Susannah has found herself with ghosts in the past. Susannah's encounters also help to unravel the secrets of missing and dead people who are associated with the family of the boy she likes, the Beaumonts. The evidence seems to point to the fact that the father of Tad, the boy she likes, is a vampire and killer of several environmentalists involved in trying to stop the development of some of his construction projects.

It starts when Susannah has a wailing woman appear in her room. The ghost asks Susannah to tell Red that he didn't kill her. When Susannah starts to investigate who Red is, it leads her to the father of the boy she meets at a pool party, Tad Beaumont's father, whose nickname is Red. As Susannah uncovers the truth, she realizes that it's not Red Beaumont who is responsible for the missing environmentalists, but it's his brother, Marcus. After getting rid of Marcus, with the help of the ghost that haunts her room, Jesse, Susannah realizes that Red is her youngest stepbrother, Doc, and the wailing ghost in her room is her stepbrother's biological mother.

In the end, Susannah is able to keep the secret from her friends and family members that she is a mediator. In the meantime, she is able stop a murderer and help a ghost and her stepbrother find peace.