Which episode knows it's not Ling's brother? How did you know?

In episode 15, Meng Juecheng's murderer is in prison, and Liu Fuling recognizes Yun Ge.

When Liu Fuling arrived at the prison, he found that the assassin turned out to be a lily girl who cured her rash, and asked the doctor to treat her too many diseases. Meng Jue explained to Liu Fuling that for the sake of safety, he asked to meet outside the palace and volunteered to investigate the assassination. Yu 'an doubts Meng Jue's intention, but Liu Fuling thinks he can take this opportunity to see his ability. Huo Guang flew into a rage and rebuked Huo Qubing for acting rashly regardless of the family's long-term glory, for fear that Liu Fuling would notice Huo Qubing's contact with other nationalities. Huo Mu came up with a countermeasure to let Huo Yu take a bath in the added water and get a skin disease. Meng Jue learned that HuoJia didn't avert suspicion, sought medical treatment with great fanfare, and decided to go to HuoFu to see HuoYu's injury at night. The Huo family guards who were on guard immediately found him. Huo Chengjun took him away and promised to let him check Huo Yu's injury and let him do something for himself. Meng Jue didn't find anything wrong after reading it. Yu' an also sent medicine to the door. Huo Guang thinks her family can be cleared of suspicion. Huo told his parents that Meng Jue was the assassin last night, and he could answer questions. Her mother is very considerate. Meng Jue went to Pingjun to find Yun Ge and learned that there was a white-haired man and a dashing son looking for Yun Ge. Huo's mother once told Cheng Jun that she had orders from the queen. Huo Guang said that Meng Jue played with Huo's family between applause, but this person couldn't stay. Huo's mother sent a bowl of "Meng Po Tang" to Huo, saying that she had arranged a better candidate in the future to make her forget about Meng Jue. Huo Cheng Jun drank it with tears in his eyes. Meng Jue was drinking in the street when he found Batuxing, a foreigner who came and went with Huo Yu. He caught up with him and the man was killed. He was put in prison as a murderer. Yun Ge woke up, but he was very weak. The bodyguard brought Yun Ge's lost luggage, and Yu 'an saw the coins that Liu Fuling gave Yachu. Liu Fuling came over and recognized the lotus sachet, so he was very excited. It turns out that Lily and Achu are the same person, and Yun Ge has been waiting for ten years. I dreamt that I was looking for Ling's brother everywhere, but Meng Jue pushed me off the cliff. She woke up and saw "Liu Changfeng". She said eagerly that she didn't assassinate the emperor. Liu Fuling holds Yun Ge's hand in a coma again. Her heart ached, especially when she learned that Yun Ge was seriously injured and fell ill, but she blamed herself. But he didn't blame Ann. He wanted to leave Yun Ge and rest in the palace. He told Ann not to tell Yun Ge his identity or reveal Yun Ge for the time being. Yu 'an told him that Batu was stabbed to death by Meng Jue. Dr. Zhang told me that the root of the disease can only be cured by looking for a doctor. Liu Fuling took care of and comforted Yun Ge. It is said that it is very similar to the person who married Sister Xu, but she has someone else in her heart, so she doesn't have to keep the agreement. Liu Fuling was very sad after hearing this. Meng Jue escaped from prison with the help of the red gang. He met Liu He, the king of Changyi, and Hou, the old man, but they didn't find him. Huo Guang was furious, sealed up Meng Jue's shop and issued a wanted order. Mother Huo took Huo to visit Shangguan Xiaomei in the palace. Mother Huo said that 3,000 beauties in the palace should not be alone. Despite Huo's objection, she promised to have a birthday wine on the eighth day.