«Guardian of the Palace» tells the story of a time when a plague spreads in Heishun (Blackwater) Town during the warring warlords, and Tianya, Wunian and Jiujiu set out on a treasure hunt to find the Golden Moon Gem that cures the plague. The warlord Feng Pei Chuan was trailing them and tried to take the gems for himself, but Tianya and the others managed to subdue Feng Pei Chuan, reclaim the gems and save the people.
Tianya and his sister are ordered by General Feng Peichuan to embark on a treasure hunt to find the Golden Moon Gem to cure the plague in Heishui Town, but General Feng Peichuan has other motives for finding this treasure.