The deaf nun was polishing the green malachite altar with a soft cloth, illuminated only by the dark red of the sanctuary light hanging from its sconce behind the altar. Then her fingers moved rapidly, spelling something: Behind you. Be careful. Behind you! Allegra whirled, drawing in her breath. In the dim light someone wielding a heavy iron shovel was rushing down the stairs toward her. When noted photographer Allegra Cesaretti flies to a monastery in Colorado for her yearly retreat, she discovers financial irregularities, two murders, the abbotÂ’s mysterious illness, and a blundering sheriff. In the end, her camera gives her the answer Â— but not before she almost becomes the next victim.