Scorched Grace by Margot Douaihy

When Saint Sebastian's School becomes the target of a shocking arson spree, the Sisters of the Sublime Blood and their surrounding community are thrust into chaos. Unsatisfied with the officials' response, sardonic and headstrong Sister Holiday becomes determined to unveil the mysterious attacker herself and return her home and sanctuary to its former peace. Her investigation leads down a twisty path of suspicion and secrets in the sticky, oppressive New Orleans heat, turning her against colleagues, students, and even fellow Sisters along the way.

Sister Holiday is more faithful than most, but she's no saint. To piece together the clues of this high-stakes mystery, she must first reckon with the sins of her chequered past - and neither task will be easy. An exciting start to Margot Douaihy's bold series that breathes new life into the hard-boiled genre, Scorched Grace is a fast-paced and punchy whodunnit that will keep readers guessing until the very end.