Poongsan, a skilled messenger, risks his life to deliver letters between families divided by the North and South Korean border. His dangerous work takes a turn when South Korean agents enlist him to smuggle In-ok, the girlfriend of a prominent North Korean defector, into the South. As they navigate the treacherous journey, the bond between Poongsan and In-ok deepens, sparking an unexpected romance amid the perilous circumstances. Their connection challenges the boundaries of loyalty and love in a divided land.