In the midst of the Great War, Margot De Wilde spends her days deciphering intercepted messages. But after a sudden loss, her world is turned upside down. Lieutenant Drake Elton returns wounded from the field, followed by a destructive enemy. Immediately smitten with Margot, how can Drake convince a girl who lives entirely in her mind that sometimes life's answers lie in the heart?

A skilled cryptographer, Zivon Marin fled Russia determined to offer his skills to the Brits. Lily Blackwell is recruited to the intelligence division to help the war with her unsurpassed camera skills. But when her photographs reveal Zivon is being followed, his loyalty is questioned and his enemies are discovered to be closer than he feared.

As part of England's most elite private investigation firm, Gemma and Graham must set aside their broken relationship to work together on a new case. Graham is determined to use this opportunity to win back the only woman he's ever loved, but there's no guarantee Gemma's shattered heart can be restored.