A young girl—a mudlark—is found dead on the muddy bank of the Thames in her best dress, a crystal perfume bottle clutched in her lifeless hand . . .

Fearing foul play, widow Amelia Greystone sends for Scotland Yard Inspector Henry Field—the man still haunted by his failure to solve her husband's murder. Though the trust between them is fragile, Amelia believes Henry is the only one capable of delivering justice.

Henry soon confirms Amelia's suspicion but is met with orders to abandon the case. He refuses to turn a blind eye and reluctantly agrees that Amelia aid him as he conducts a clandestine investigation.

As secrets unravel, a second body surfaces, and the pair unearth a plot with chilling ties to the government. When Amelia's personal demons threaten to drive her into the killer's path, Henry must confront his own fears to not only save her but stop the villain.