Cece Monroe—the former Sister Mary Cecelia—is an ex-nun who finds herself in the middle of a murder investigation...and possibly the killer's next victim.

After mistakenly hearing a senator's incriminating confession just moments before he is murdered, Cece refuses to spill the details of his secret to authorities, even though she is the closest thing to a witness they have. According to Cece, "What happens in the confessional stays in the confessional," but the Feds want answers. Army ranger turned police detective, Ace Jackson, isn't thrilled when he's assigned to nun-sit while the investigation unfolds, ordered to keep his disconcertingly attractive charge safe at all costs.

That turns out to be easier said than done when Sister Mary Sleuth drags Ace through a series of misadventures and crazy encounters as she attempts to solve the case herself, despite a ruthless assassin who keeps popping up to take potshots at her.