In the third installment of Margot Douaihy’s USA Today bestselling mystery series, punk rock nun-detective Sister Holiday must dive into the dark underbelly of New Orleans’ drug epidemic to solve a deeply personal case.

It’s a steamy, restless end of the school year in New Orleans. Sister Holiday is staying busy with her music classes and preparing for her permanent vow ceremony, a pivotal moment in her journey of faith. But when one of her favorite students is found dead of a fentanyl overdose, Sister Holiday and her partner-in-PI, Magnolia Riveaux, are launched on a mission to track down the drug dealers. As students continue to fall prey to this sinister drug under her watch, Sister Holiday becomes more and more desperate to stop this epidemic. All the while, she must contend with her own past with addiction, a demon that is never too far.

Sister Holiday’s darkest and most shocking case yet will test the limits of her faith --- and her sanity --- as she goes deep undercover with a local gang and ultimately uncovers a truth with lethal implications for those she loves. With Douaihy's signature mix of grit, heart and faith, DIVINE RUIN is a stunning and timely addition to a one-of-a-kind series.