It's 1941 and the country has been turned upside down. For the aristocratic Walsingham family this means their grand home is taken over by the Army. Ava and Maudie are at Walsingham Hall to become code girls and break German encryptions. So being sent downstairs to work in the kitchens isn't exactly what they had in mind. But they do their duty and though life is tough, it has never been more exciting. Meanwhile, upstairs, Lord Walsingham is hiding something. Maudie and the girls realize the safety of their country might actually be in their hands after all .