Farm dog, Tierza, is devoted to her human boy, Aaron. Their idyllic life is interrupted when the German army invades. Forced from their farm, Tierza accompanies her family to the Warsaw ghetto. Together with her boy, they try to live as normal a life as possible under terrible circumstances. For Tierza, all of that ends when her Aaron is taken by German soldiers and forced onto a train. Relentlessly, she follows the train tracks. During her journey, she meets different people and tries her best to aid them any way she can, but she never stays for long. Her love for her boy drives her onward to the end of the tracks and her boy’s fate.