Finances are very tight at the convent, so Sister Joan is dispatched to the attic storerooms to clean out old items and look for anything which might have enough value to be sold. In the course of her housekeeping chores, she discovers some mysterious footprints and begins to do some research on the convent's original owners. Dead bodies begin to appear, and as usual, Sister Joan does her own sleuthing, independent of Detective Sergeant Mill. This book differs from others in the series in that the solution to the murders is gradually revealed throughout the story and the only task left is to apprehend the murderer. The other nuns and some townspeople serve to round out the cast of characters, and reliable author Black spins another interesting tale.