Rhode Island bookshop owner Penelope McClure never believed in ghosts -- until she met the spirit of Jack Shepard, a big city private investigator who was gunned down in her store over sixty years ago. Now Penelope not only believes in her hard-boiled ghost, she asks for his help in solving a murder.

A loyal customer of Penelope's bookshop has been found dead on posh Larchmont Avenue. The elderly woman left a will that was recently (and suspiciously) revised to name her mailman, Seymour Tarnish, the sole heir to her estate. Many eyes in the little town turn to the hapless mailman as the murderer, including the town's police chief, but Seymour doesn't care. He's too busy settling into his posh new digs. Unfortunately, Seymour's new mansion also appears to be haunted and when the mansion's ghosts begin plaguing him, he hires a team of parapsychologists to exorcise every last spirit from the entire town. Now Penelope must not only solve a murder, and prove her friend Seymour innocent, she must act fast to save her beloved ghost; because if these "spirit zappers" actually do their job, then the ghost of Jack Shepard finally will be history. And that scares Pen a lot more than rattling chains and cold spots.