The two figures had been on the bridge. He had grasped hold of her. To save her, or to push her?Inspector William Monk is still feeling his way in a new post in the Thames River Police and knows he must solve the mystery to gain the respect of his men.Soon both he and Hester find themselves powerfully involved in the story of the dead woman, Mary Havilland, and her quest to vindicate her father, found dead two months previously.An engineer working for the Argyll Construction Company, James Havilland was convinced a major disaster would happen in the tunnels where London's desperately needed new sewer system was being built.Maddened by his obsession, he'd apparently shot himself.Mary had never accepted that and now she was dead too.Was it chance or something more sinister?