Nirvana in Fire Episode 49

After reading his confession and finding evidence of the poison in the palace books, the emperor allows Xia Jiang to see him. The emperor also summons Mei Changsu and forces Meng Zhi to take leave. However, Gao Zhan secretly tells Consort Jing's maid to not let Mei go to the palace. Consort Jing passes the message to Prince Jing, but he could not stop Mei in time. The Emperor then summons Prince Jing and Xia Jiang; Xia Jiang accuses that Mei Changsu is Lin Shu and it was he who helped Prince Jing rise in power. However, he fails and is imprisoned again. The emperor also attempts to kill Mei Changsu himself, to prevent anymore problems, but he is stopped by Prince Jing. Prince Jing finally realizes Mei Changsu's true identity. (Source: Wikipedia)