Detective Inspector Arthur Gredge of Scotland Yard is a changed man, and not for the better it seems. The prime suspect in a terrible crime he did not commit, Gredge launches an impassioned defence. The problem is that he does not know if he is guilty or innocent.
 
Midnight Gunn must uncover the cause of Gredge's unsettling behaviour before the Inspector loses his mind, his job, or very possibly his life. It is a task that must be conducted with the upmost caution as Midnight's own conduct comes under close scrutiny from all directions, putting his entire existence, and that of those he loves at risk.
 
Could a long-forgotten artefact hold the key to it all? How much is Midnight willing to risk exposure to help the friend who has shunned him? What secrets will he uncover about his own origins along the way?