After her parents divorced, Lin Qi received two house keys, thinking both sides were her home. But overnight, both parents changed their locks, and her old keys completely failed. She accommodated everyone and tried to be sensible everywhere, yet in the reconstituted families she was always an outsider, and her household registration was even rejected and passed back and forth by both sides. Seeing through the thinness of family affection, Lin Qi blocked her parents and traveled far away to the mountains to teach. Years later, her parents woke up to their faults and rushed to the mountain village to take her home, promising to make up for what they owed. But the cracks could no longer be repaired, and her true home is that door in the mountains that is truly open for her.