September 1941. While on a delivery, young Freddie Hackett, a message runner for a government office, witnesses an argument that ends in murder. Crouching in the doorway of a bombed-out house, Freddie waits until the coast is clear. But when he arrives at the delivery address, he's shocked to come face to face with the killer. Dismissed by the police when he attempts to report the crime, Freddie goes in search of a woman he once met when delivering a message: Maisie Dobbs. While Maisie believes the boy and wants to help, she must maintain extreme caution: she's working secretly for the Special Operations Executive, assessing candidates for crucial work with the French resistance. Her two worlds collide when she spots the killer in a place she least expects. She soon realizes she's been pulled into the orbit of a man who has his own reasons to kill, reasons that go back to the last war.