The Music Box is the treasure of Yin-yang School, and it was somehow taken to Mohist School. The children realize they have to pass the test of the box to survive. A starry sky appears above them, and Yue-er finds out part of the secret with her knowledge about the Five Elements, the Twelve tones and Five sounds. She remembers how her mother has taught her to watch the stars, and find the vital star, the key to the test. Yue-er takes the box with her when they leave. Gongshu Chou manages to enter the Forbidden Land. The children come to a place with two roads. When they go to read the words separately, Shaoyu stands at the entrance to the Kingly Path, Tianming and Yue-er at the Chivalrous Path.
“龙喉”机关中，高月认出了三人面前的那个音盒是赫赫有名的幻音宝盒，这时在三人上方出现了黄道星图。密室中众人得知三人到达了“龙喉”都十分担心，然而高月仔细地观察密室，从中获得线索信息，她以过人的见识和冷静的头脑最终解开了幻音宝盒的奥秘，令三人脱离险境。接下来，出现在三人面前的是两条不同的道路。
