Five years after leaving the Miami PD, ex-cop Hannah Keller still can't escape the memories of her disastrous final case: of how her young son saw his grandparents murdered in front of his eyes and how she failed to find their killer.
In her new career as a crime novelist she has tried to put those terrible events behind her - until the day she stumbles across a copy of her first novel covered in strange cryptic markings. She realises that these are not the ravings of a madman but a code that could lead to the murderer.
The challenge is irresistible, but soon she finds herself caught up in an FBI scheme that hurtles wildly out of control, leaving Hannah and her son running for their lives from the hitman from hell.
