Charli Rae Warren doesn’t plan on striking it rich as the owner of an independent bookstore in Hazel Rock, Texas—especially one with a pink armadillo as its mascot. But when an ingenious advertising campaign puts her business on the map, it ropes in some deadly publicity . . .

Charli can’t believe writer Lucy Barton has agreed to promote her latest Midnight Poet Society novel at The Book Barn Princess—or that there’s only a week-and-a-half to prepare for the signing. It’s all because of The Book Seekers, a smartphone app created by her cousin Jamal exclusively for Charli’s bookstore, which sends fans on a virtual scavenger hunt around town for a chance to meet the bestselling author. But as soon as it goes live, people turn up dead . . .

Someone’s using The Book Seekers to track victims and copycat the fictional Midnight Poet Society homicides, and horrified locals suspect Jamal could be the mastermind behind the crimes. While Charli readies the Barn for a stampede of new customers, it’ll take true grit to shelve the culprit before her brainy cousin gets locked behind bars, Ms. Barton backs out of the visit, and she finds herself up a creek—with a serial killer holding the paddle!