Certainly in Reggie Fortune's lifetime he had never encountered evil in a more virulent form than it functioned at Hurst parish, though he might well have passed the case by as a dull one - had he not found a dead bat in the church's bell tower. It was after the third murder was committed, much to Reggie's chagrin, that he said, "Until we know why Mrs. Carson went to church, we don't know where we are"....
With the aid of blood groupings, and with his discovery of the reason why the minister failed to appear at the church one afternoon at his customary time, Reggie succeeded in discovering one of the most vicious individuals it had ever been his misfortune to match wits against.