Mara Galanta is The Lady of the Walls, an opera singer who sprang to fame when she sang at the Berlin Wall in 1972. Ever since that wondrous moment, people from across the world have been writing to her to tell her about their own walls. Mara is rebellious, rich, and talented. She is also a careless, irritable, and lonely old lady.

Her granddaughter Emma ​​inherited her artistic sensibility and her impetuosity. While trying to establish her own identity, she grows curious about her grandmother's past, and organises a trip to Mara's homeland, Latvia, which she fled at the age of 18 when it came under Soviet dictatorship. The Iron Curtain has long since fallen, but Mara has never returned. And she never talks about her native land.

Emma is determined to uncover her secrets, but little does she know that a mysterious old woman and a little magic will take them on a journey through time and history that will rekindle long dormant memories.