Anna Neagle is a WWII WREN---the counterpart of the American WAVE---who encounters Michael Wilding in a blacked-out Piccadilly during an air raid. They get married and have a two-day honeymoon before she is sent to Singapore. The ship in which she leaves the doomed-fortress of Singapore is torpedoed, with all hands posted as drowned. Not quite. She's cast away on an unknown South Sea island for three years with a company of sailors. Wilding, unaware of this circumstance, marries again, this time to an American girl, and they have a child. And, then, Anna returns.