Nirvana in Fire Episode 5

The three children compete with Baili Qi, and eventually win. After the match, Princess Nihuang conveys her suspicions to Mei Changsu, who informs her that the match was fixed; Baili Qi is actually a member of the Jiang Zuo Alliance, and the events leading up to the match were arranged in order to secure Tingshen's freedom. Mei then warns Nihuang to be careful of what she eats or drinks when she is summoned by the Empress. However, he soon realizes that the Empress is not the one behind the act, but Noble Consort Yue. He quickly arranges for Meng Zhi to notify Prince Jing to save Nihuang. Prince Jing arrives at Zhaoren Palace to save the unconscious princess. The Empress soon arrives to the palace as well, and reports to the Emperor of the incident. The Emperor finds Noble Consort Yue guilty, demotes her to concubine, and grounds her son. (Source: Wikipedia)