As one of the Navy's most skilled mapmakers, Merry knows the very lives of men far away depend on her work in the War Office. But when a family crisis draws her back to her beloved Cornwall, Merry finds herself working alongside an enigmatic American officer on secret operations spanning the rugged coasts of Cornwall and Brittany which she knows so well. But not everything is as clear as the maps she draws. As rumours and suspicion swirl around her family, Merry is increasingly drawn to Jake, despite the defences she's built around her heart. It's a dangerous time to fall in love when there is everything to lose as the tides of war are rising.