Whicher is hired by his one-time political master, former home secretary Edward Shore, to investigate threats made against his son Charles, who has recently returned to London from India with his young family. Shore fears entanglement in a scandal could have devastating repercussions for his career and insists the detective carry out the investigation without involving his former Met colleagues, even after a murder occurs. Whicher's pursuit of justice takes him to the most dangerous corners of the Docklands, but also brings him into contact with a woman who starts to melt his long-frozen heart.