Kate Rees, a young American markswoman, has been recruited by British intelligence to drop into Paris with a dangerous assignment: assassinate the Fuhrer. Wrecked by grief after a Luftwaffe bombing killed her husband and infant daughter, she is armed with a rifle, a vendetta, and a fierce resolve. But other than rushed and rudimentary instruction, she has no formal spy training. Thrust into the red-hot center of the war, a country girl from rural Oregon finds herself holding the fate of the world in her hands.

Maggie Hope has come a long way since she was Mr. Churchill’s secretary. In the face of tremendous danger, she’s learned espionage, sabotage, and reconnaissance. But things are different now that she has so much to lose, including the possibility of a family with John Sterling, the man who’s long held her heart.

Singapore, 1910 - Desperate for a fresh start, Harriet Gordon finds herself living with her brother, a reverend and headmaster of a school for boys, in Singapore at the height of colonial rule. Hoping to gain some financial independence, she advertises her services as a personal secretary. It is unfortunate that she should discover her first client, Sir Oswald Newbold - explorer, mine magnate, and president of the exclusive Explorers and Geographers Club - dead with a knife in his throat.

England, 1943: Deciding to throw herself into war work, Nancy Callaghan joins the Special Operations Executive in Baker Street. There, she begins solving ‘indecipherables’ – scrambled messages from agents in the field. Then Nancy meets Tom Lockwood, a quiet genius when it comes to coding. Together they come up with the idea of printing codes on silk, so agents can hide them in their clothing to avoid detection by the enemy. Nancy and Tom grow close, and soon she is hopelessly in love. But there is a traitor in Baker Street, and suspicions turn towards Tom.

Olivia Denis is a content young wife with a carefree life in late 1930s London. Then her world is shattered with the violent death of her husband, Reggie. The police want to call it a suicide and close the case, but Olivia knows Reggie couldn't possibly have fired the fatal shot. Further mysteries surface surrounding her husband's death. Did the trustworthy Foreign Office employee betray government secrets? Was his murder linked to the death of a German embassy clerk the same night? And who searched their flat?