Brothers Keepers — Donald E. Westlake

"Bless me, Father, for I have sinned," confessed Brother Benedict of Manhattan's Crispinite Order. And that was before the 19-year lease on the order's Park Avenue monastery had expired, pitting its sixteen monks against a greedy real-estate mogul who could quote Scripture like a pro. And that was before Brother Benedict fell head-over-heels in love with the greedy landlord's daughter...

Suddenly, from Midtown to the Caribbean, Brother Benedict has to play detective and ladies' man in the noisy, profane, and inexplicable world outside the monastery. And Brother Benedict had better not trip on his robe. Because, although he's trying to save a house of God, all hell is about to break loose.