Yong-soo is an ex-soccer player who lives in a small coal-mine village in North Korea with his wife and young son, Joon. Although living in extreme poverty like many other families in North Korea, the family is happy just to be with each other. Then one day, Yong-soo's pregnant wife becomes critically ill.
Let alone medicine, Yong-soo can't even find food for her in North Korea. So he decides to secretly cross the border to China hoping to find the medicine for his wife. Yong-soo makes a promise to his young son Joon. He tells Joon to take care of his mother in his absence, for he will return with food and medicine in just 10 days.
After many life threatening moments in China, Yong-soo is forced into South Korea, becoming an unwanted refugee prohibited from returing to his family. Meanwhile, his wife passes away, leaving young Joon alone in desperation. As his father had, Joon attempts to cross the river to go to China. But, he is captured near the border by North Korean guards.
He is sent to a youth detention camp where he is beaten with guns and shovels, forced into hard labor during the day and locked up in a cell at night. In South Korea, Yong-soo searches ways to safely bring his son to him.