In the future world, in the century-old house of the Gu family, the top conglomerate, every daughter-in-law who enters the house will "mysteriously disappear" three months after their marriage, and even the police have no clue. Lin Chen, the sister of escape room designer Lin Wan, is the last missing daughter-in-law of the Gu family. She found clues that "the walls of the old house are talking" in the diary left by her sister. In order to investigate the truth, she took the initiative to marry Gu Mingxuan, the only son of the Gu family, and entered the old house. However, the "owner" of the old house's intelligent system seems to have self-awareness and locks all exits at 12 o'clock every night. Each floor becomes a "secret room" that needs to be cracked - the kitchen on the first floor hides my sister's nails, the study on the second floor has tampered surveillance, and the bedroom on the third floor has a strange distress signal. Lin Wan used her secret room design skills to solve the puzzle step by step and discovered that the Gu family was actually using the old house to conduct a "family gene optimization experiment" and that the missing daughter-in-law was a "sample" of failed experiments. Mother-in-law Suman and sister-in-law Gu Wei are the executors of the experiment. They want to turn Lin Wan into the next "sample." With the help of Gu Zhao, the maintainer of the old house, Lin Wan finally found the whereabouts of her sister (who was imprisoned in the basement), and revealed the Gu family's conspiracy, bringing to light the future evil hidden in the deep house.
