When a group shot the movie "blood ghost" in an ancient castle, the actress disappeared in the bathtub during the filming. The crew opened the bubble in the bathtub, leaving only a pool of blood and water. At that time, the castle gate was closed and the entire crew was missing. When Qian Shu and Ma Xiaoliu saw this news video, they saw a butterfly with strange colors flying out of the castle. At the same time, Ma Xiaowu, who was guarding the cemetery, found that the patterns carved on the white marble columns in the cemetery had all turned into butterflies. Qian Shu has been exploring the entrance of the underground palace of the imperial mausoleum. This series of changes guide Qian Shu to find the answer. He believes that the underground palace gate will be opened for him soon.