In May 1941 Lena Mukhina was an ordinary teenage girl, living in Leningrad, worrying about her homework and whether Vova - the boy she liked - liked her. Like a good Soviet schoolgirl, she was also diligently learning German, the language of Russia's Nazi ally. And she was keeping a diary, in which she recorded her hopes and dreams. Then, on 22 June 1941, Hitler broke his pact with Stalin and declared war on the Soviet Union.