"Beijing No. 81 2" is based on the true story of Beijing No. 81 Underground Palace, the first of the four major haunted houses in the East. At the end of the Republic of China, it was a time of chaos. The warlords in Beijing mutinied, and the young marshal Zhang Zhisheng (played by Julian Cheung) was forced to marry the daughter of a big warlord, Ji Jincui (played by Gillian Chung). Then strange things happened in the mansion, and people were in panic. Soon after, a large number of "corpse baby cases" emerged in Beijing, and all the spearheads pointed to the young marshal's original wife Niu Menghe (played by Mei Ting). Then Niu Menghe disappeared strangely, and No. 81 Beijing was tragically wiped out overnight, leaving behind a dilapidated haunted house. A hundred years later, cultural relic restorer Song Teng dug up a large number of baby bones and strange spells in the process of repairing the ancient house. One bloody old incident after another seemed to drag everyone into the abyss. The grievances and hatreds of past lives emerged one by one, and the story of the ghosts in the underground palace asking for their lives began...