Crime wave in a mezzo-progressive Ohio convent--beginning with the overdose death of a jittery sister (accident? suicide?) and investigated by Lieut. Bob DiVencenzo, who seems to be as interested in bending the vows of comely Mother Superior Karen as in solving the accumulating murders. Karen, attired in cautious chic and plagued by doubts and sexy dreams, is not exactly resistant to the cop's come-ons. . . until she begins to suspect surprising ulterior motives behind the badge. Sister Karen's blessedly un-perky charms are Cullinan's main attraction; though brightly paced, the whodunitry--exposing the nunnery as a veritable castle of vice--teems with unlikely ways, motives, and means.