Queensrÿche in 1988 gave us the rock opera Operation: Mindcrime. It tells the tale of Nikki who succumbs to the underworld of crime.
We learn of his love of a nun, Sister Mary, who later gets killed. The lyrics of "Spreading The Disease" speak of prostitution. So I wonder if she was the prostitute.
The underworld boss instructs Nikki to kill her, making me think she is a loose end, possibly already having had untoward relations with the boss.