On the day of the triplet’s birthday party, Jiu Shi and Lan Zhan try fire against the Master, who becomes angry and chases them. They end up on the 7th floor, which the Master can’t enter. They realize the Master is the little boy in 2010 who took the time machine in 2040 to try and save his mother but ended up in 1985 when his mother was one of the three 10-year-old triplets. (Source: frankly at kisskh)