Mrs. Watson and the Death Cult — Michael Mallory

When the body of a prominent businessman is found floating in an ancient Roman bath, all the evidence points to a young man named Ronald Standish as the murderer. His wife appeals to her old governess Amelia, the second wife of Dr. John H. Watson, for help. Soon, Amelia is thrust into a baffling mystery involving the practice of ancient pagan religious rites in the modern city of Bath. At every step, though, she finds evidence that makes the case against Standish even stronger...