The eighth mystifying William Monk novel from Anne Perry

In the dead of night in a notorious area of Victorian London's East End known as St Giles a factory girl stumbles over the bloody bodies of two City gentlemen. When Detective John Evan finally arrives at the scene, he is confronted by a most difficult investigation. First he must identify the men. Then he must find out why men of means and social standing would go to such a sordid area. Most importantly, who are their assailants? And how could they escape unharmed and unnoticed?
Mercifully the younger victim is not quite dead. Having sustained terrible internal injuries, he's later released home from hospital severely traumatised and unable to speak - to be told that the other victim, his father, is dead, and Hester Latterly has been employed to help nurse him back to full recovery.
With too many obstacles impeding his progress, Evan finally enlists the aid of his old friend, William Monk, who, together with Hester's help, must unravel one of his most complex and shocking cases yet.