Tom Spears is not proud to be a professional killer. He never sought the reputation that precedes him, the one summed up in the sobriquet "The Shadow." He once worked for the Manatone family, a powerful branch of the New York mob. Then Spears killed one of them. Now those that remain seek his life. They kidnap Spears' wife, Tanya, sending him on a nationwide search. If an activity is illegal, the Manatones are involved, and growing marijuana is fair game. In the growing fields of upstate New York, Spears discovers that "The Shadow" is a rallying cry for six displaced children of murdered field workers. His quest expands to include avenging the children. A Mexican cartel tries to steal the Manatones' monopoly on the product. However, Spears doesn't care who grows the weed, as long as he can eliminate those who would harm the woman and children he loves.
This volume picks up seamlessly where the third book in the series ends. Diffley's writing is as tense and secretive, when appropriate, as the planning sessions for the mob hits it describes. His action sequences, by contrast, release that tension with their intense imagery that does not flinch from the gory details of assassination. Diffley avoids developing his child characters according to hackneyed tropes. Instead, he imbues all of them, and Maria in particular, with wisdom and intelligence beyond their years in keeping with their enforced self-reliance. Female thriller fans may well be drawn to the presence of multiple strong, resourceful woman and girl characters. However, the strong anti-gay sentiments many of the characters openly express may put off some readers. That said, the theme of the mobsters' selfish ambition versus the altruistic concern Spears, Tanya, and the children experience for one another runs throughout.