Ryoo Seung-bum stars as Nam Chul-woo, a poor fisherman living a simple life in North Korea with his wife and daughter.<ref name=":0" /> One day his net gets caught in his engine, and he is suspected of being either a defector or a spy when his boat accidentally drifts into South Korean waters. He endures interrogation, beatings, and more in his attempt to return to his family, even as he comes to the realization that his life will never be the same.