No one knows where the new girl at the gymnasium came from - Varya Chudarina, a girl surrounded by mysteries. The sky outside the school windows is smoked by pipes, steel zeppelins glide among the clouds. Guardians clad in black uniforms walk the streets. Varya has a dangerous secret, because of which she has to be afraid. Afraid of everything: every knock on the door and every figure on the street. It seems that everything is hopeless. But she finds an unexpected friend at the gymnasium and goes with him in search of terrible secrets. Where has her dad gone? What is the Master hiding behind the walls of his tower? And what if Varya’s most important secret is hidden inside herself?