There's an old Cornish saying: "Save a stranger from the sea, he'll turn your enemy ..." When her reclusive grandmother Jaunty becomes too frail to live alone, Gabriella Blythe moves into the remote waterside cabin on Frenchman's Creek which has been her grandmother's home for decades. Once a celebrated artist, Jaunty's days are coming to a close but she is still haunted by events in her past, particularly the sinking of a ship during the war. Everything is fine until a handsome stranger arrives in a storm, seeking help. Fin has been left a family legacy: a delicate watercolour of a cabin which leads him to this beautiful stretch of Cornish water. As Fin begins to pick at the clues of the painting, he is drawn into the lives of Gabe and Jaunty, unravelling a remarkable story of identity and betrayal ...