1552, Paris: The printing press is quickly spreading new ideas across Europe, threatening the power of church and state and unleashing a wave of book burning and heretic hunting. When frightened ex-nun Lysbette Angiers arrives one day at Charlotte Guillard’s printing shop with her manuscript, neither woman knows just how far the elite will go to prevent the spread of Lysbette’s audacious ideas. 1952, New York: Milly Bennett, is a seemingly ordinary housewife with a secretive past. She finds her life taking an unexpected turn as conspiracies spread amidst the paranoid clamors of McCarthy’s America. When a relic from her past presents her with a 400-year-old manuscript to decipher, she is pulled into a vortex of danger. The stakes couldn’t be higher when, 400 years apart, Milly, Lysbette and Charlotte each face a reality where the spread of ideas are feared and every effort is made to suppress them.

London, 1962: Celia Duchesne longs for a career, but with no means or qualifications, she passes her time working at a dusty bookshop. The day a handsome American enters the shop, she thinks she might have found her way out of the monotony. Just as the excitement of a budding relationship engulfs her, a devastating secret draws her into the murky world of espionage. France, 1942: Nineteen-year-old Anya Moreau was dropped behind enemy lines to aid the resistance, sending messages back home to London via wireless transmitter. When she was cruelly betrayed, evidence of her legacy and the truth of her actions were buried by wartime injustices. As Celia learns more about Anya --- and her unexpected connection to the undercover agent --- she becomes increasingly aware of furious efforts to protect state secrets.