Twelve-year-old Isabel and her mother, who was a famous political singer, had to escape Chile after the 1973 military coup. Isabel’s father stayed behind fighting in the underground. For six years, they have lived in a new apartment building in East Berlin. At first, the neighbors made an effort to welcome them, but later became more distant. Isabel does not feel at home in the strange country. Not even her friendship to Philip, the neighbors’ son, can change her mind. Almost every day, Isabel sits on the stairs waiting for a letter from her father, from whom she has not heard for many years.

The real blue is the color with which potter Benito Guerrero makes his fortune. When he no longer receives the color from Germany as a result of the Second World War, he and his family's existence are threatened. However, with the help of his inventive cousin Ruben, he manages to bring his real blue back onto the market.