World War II. Nazi-occupied Ukraine. Germans set up a camp called "Hope", a site of medical experiments on children. Twins are designated as experimental subjects. So when one of the twins, Petya, escapes from the camp, the Germans raise an alarm, trying to find the runaway. The life of the entire village turns to hell: partisans need to consider their hide-outs with extreme prudence, locals are suffering from inspections and local police are doing their best to find the escapee.