A Good Girl's Guide to Murder meets Fargo in this fast-paced YA mystery about a teen detective gone missing and her best friend who must finish her investigation.

Seventeen-year-old Fenny Allen has been Sarah Vincenty's sidekick for as long as she can remember, ever since the two of them solved the mystery of the stolen library books back in elementary school. Over the years, Sarah has ruffled a few feathers in their small town, building a reputation as both an amateur detective and a vigilante who has dispensed her own form of justice.

Now Sarah is missing. The police have written her off as yet another teen runaway, but Fenny is convinced that something more sinister has happened. When she discovers a binder Sarah left behind entitled In Case I Go Missing, Fenny learns that at the time of her disappearance, Sarah was investigating her biggest case yet.

Fenny knows that it's up to her to finish what Sarah had begun. As she and her friend Sam piece together the clues that Sarah left for them, they find themselves up against a decades-old mystery-one that links to the town's dark history. But is this binder a guide to finding Sarah-or are Fenny and Sam already too late?

The more the pair uncover, the clearer it becomes that those involved will go to great lengths to keep their secrets-even as far as murder.