Episode 21 recap: Chun Yu is one of the founders of the 19th Floor.

Chun Yu was searching through Lao Lin's belongings in the dormitory when she found a valuable computer that aroused her suspicion. While she was trying to decipher the password, Lao Lin was on his way to the dormitory. Upon his arrival, Chun Yu quickly put down the computer and looked at Lao Lin. Just as she was about to greet him, their roommate walked in and mistook Chun Yu for Lao Lin's daughter. The roommate even mentioned how well Lao Lin treated her and specially bought her a computer. As the roommate spoke, she took out the computer. Lao Lin hurriedly stopped the roommate and explained that it wasn't true. Meanwhile, Chun Yu's grandmother tried to enter the school but was stopped by the security guards. Chun Yu and Lao Lin rushed to the entrance to resolve the conflict.

Xu Wen Ya came to attend class and encountered Xiao Qin, who was also taking the same course. They comforted each other and encouraged one another to look ahead. Chun Yu's grandmother accidentally twisted her waist while walking, so Lao Lin and Chun Yu helped her back home. Chun Yu took the opportunity to pour water and intentionally wet Lao Lin's notebook, but she discovered that Lao Lin cared a lot about that notebook. Her plan failed. Chun Yu saw dumpling filling on the table and deliberately dragged Lao Lin into making dumplings together. The electric cooker at home was damaged, and Lao Lin voluntarily repaired it, which once again aroused suspicion in Chun Yu.

Gao Xuan secretly entered Chun Yu's office, but Director Yan had already discovered him in the dark. Gao Xuan found Chun Yu's work ID card and noticed that the computer was turned on. When he opened it, he found that the online gaming username was the same as that of an online friend. He suspected that the online friend was Chun Yu.

Lao Lin skillfully fixed the electric cooker, revealing that he had worked as an electrician before. While they were making dumplings, Chun Yu seized the opportunity to tamper with Lao Lin's notebook. At that moment, Chun Yu's grandmother walked in and wiped the flour off Chun Yu's face. This scene moved Lao Lin, and tears welled up in his eyes. Lao Lin, Chun Yu, and her grandmother sat together eating dumplings. Chun Yu unintentionally stared at the little notebook, and Lao Lin voluntarily handed it to her. It turned out to be a collection of recipes and cooking tips that he regularly recorded.

Gao Xuan contacted his online friend as soon as he got home to confirm if he was Chun Yu. The username "Mazorini" made Chun Yu suspect once again the connection between Gao Xuan and Chun Yu. Chun Yu messaged Gao Xuan, and when he stood up to reply, his notebook was invaded by Yan Ming Liang, who watched him through the camera.

While Gao Xuan was not at home, Chun Yu sneaked into his dormitory and directly opened his computer. She deciphered it based on the day they first met and arranged a meeting with Mazorini. Gao Xuan secretly infiltrated MicroTech at night, but all of this was monitored by Director Yan. Gao Xuan opened a yellow safe, wanting to see the so-called self-developed equipment. Since it was locked and couldn't be opened, Director Yan remotely unlocked it and watched Gao Xuan take something from inside before feeling relieved. It turned out that Director Yan wanted to use Gao Xuan to deal with the 19th Floor and save his daughter.

Mazorini suddenly replied agreeing to the meeting, and Chun Yu hurriedly went to the agreed location after seeing the response. When Gao Xuan returned home and took out the stolen buffering device, he couldn't wait to tell Chun Yu the news, but before he could say anything, the device started sparking. Gao Xuan was investigating why the device was malfunctioning when Chun Yu entered Tianji Technology and discovered that the company had given her instructions. She followed the arrows to a secret room, and the door opened automatically. From a distance, she saw Chun Yu lying there unconscious with a breathing apparatus, and next to him was a gaming helmet. The display screen indicated that she should put it on.

Chun Yu put on the helmet and saw her father inside. Chun Yu's father had been waiting for her all along. He showed her the various circuits and screens in his house and complained that nobody could understand him. He felt that as a genius, he shouldn't be living a mundane life in such a family. Later, he found like-minded Yan Ming Liang and collaborated with him to create the 19th Floor. Yan Ming Liang highly approved of the 19th Floor, but Chun Yu's father felt the game lacked a soul. In a visit to the game, Yan Ming Liang had an accident and fell into a coma. Chun Yu's father returned to the real world and used the system to restore Yan Ming Liang's consciousness, bringing him back to life. This thrilling event was exactly what Chun Yu's father had been pursuing.