Meng Jie is the fictional elder brother of Meng Huo and Meng You. Unlike his two younger brothers, Meng Jie had refused to live the way of his people and adopted the lifestyle of the Han. He ocuppies as a hermit living in the southern part of the Kingdom of Shu, near the land where his brother ruled. Once, Zhuge Liang, the Prime Minister of the Kingdom of Shu, led an army to pacify the southern barbarians in the Southern Campaign who had rebelled against the sovereign ruler Liu Shan.
On the way, Zhuge Liang had managed to defeat Meng Huo and had captured and released Meng Huo four times. This time, Meng Huo had sought refuge under another barbaric ruler named King Duosi and they had made plans to attack the Shu troops. They obstructed the main road leading to their hideout, forcing the Shu troops to take the other path instead. The other path was full of danger and suspense, with four poison springs and a forest shrouded in poisonous mist.
The unsuspecting Shu troops drank the water from the poison springs and some of them became temporarily blind, mute or deaf. Zhuge Liang was extremely worried about the situation and feared that his campaign might have to end up in failure. At that critical moment, Meng Jie appeared to Zhuge Liang and managed to aid him in healing the troops. Also, Meng Jie warned Zhuge Liang about the four poison springs and the poisonous mist. He also provided the Shu troops with a certain kind of herb, which the troops need to just put a piece of leaf from the herb in their mouths and would not be affected by the poison mist.
Zhuge Liang was extremely grateful to Meng Jie for his help and later managed to pacify the southern barbarians and made Meng Huo pledge loyalty to Shu forever.