The White Bone Demon was a corpse on White Tiger Ridge that had cultivated for many years and become a spirit. Hearing that the pilgrims would pass that way, and learning that Tang Sanzang was a good man of ten lives of cultivation whose flesh would lengthen her years, she lay in wait in the ridge for her moment.
That noon Tang Sanzang was hungry, and Wukong took his leave and rode his cloud alone to the southern hills to pick peaches; Bajie and Sha Seng stayed to watch the luggage, and Tang Sanzang sat waiting by the road.
Seeing Wukong gone, the White Bone Demon took the shape of a young woman, a blue earthenware pot in her left hand and a green porcelain jar in her right, saying that the pot held fragrant rice and the jar fried gluten, and came along the mountain road towards Tang Sanzang.
Coming back with the peaches, Wukong saw from the air that the woman was wrapped in a layer of dark vapour and knew her for a demon. Without stopping to explain to his master he brought his cloud down and struck at her head with the golden staff.
Seeing the staff coming, the woman used the art of shedding the body: her spirit escaped into the air and left a false corpse on the ground. Tang Sanzang was appalled, believing that Wukong had killed a commoner for nothing, and recited the band-tightening spell in punishment; Wukong fell to the ground clutching his head in pain.
Bajie made it worse from the side, saying that Wukong had taken the chance to kill a mortal and keep the food for himself. Tang Sanzang believed him and several times tried to send Wukong away, and only Wukong’s hard pleading kept him, ordered to follow and make amends.
Unwilling to leave it, the White Bone Demon changed again, this time into an old woman leaning on a bamboo stick, coming along weeping and saying that she was looking for her lost daughter.
Wukong saw that the demonic air on the ridge had not cleared and was the same as before, and struck again with the staff. The old woman used the same trick, her spirit escaping and leaving another false corpse on the ground. Tang Sanzang, furious again, recited the spell without stopping, and Wukong lay on the ground and begged, saying only that the demon was not dead and would come again.
Twice foiled, the White Bone Demon would not give up, and the third time became a white-haired old man, calling out for his lost wife and daughter as he hobbled along on a staff.
Fearing that this time she would escape again without trace, Wukong quietly called up the local earth god and the mountain spirit and set a net on every side so that the demonic air could not slip away; then he struck once, and killed the true White Bone Demon, who showed her original shape — a pile of bones with the words “Lady White Bone” carved on the spine.
Seeing that all three killed under Wukong’s staff had been in human shape, Tang Sanzang, with only a mortal’s eyes, would not believe that they were demons in disguise. Certain that Wukong was cruel by nature and would not be taught, he took out paper and brush and wrote a letter of dismissal.
Tang Sanzang gave the letter to Wukong and ordered him to go at once and never return to his side. Wukong knelt on both knees, took his leave in tears, and watched his master turn away as he went back to Mount Huaguo.
Tang Sanzang went on west with Bajie and Sha Seng, and was taken by the Yellow Robe Monster at the kingdom of Baoxiang and nearly killed; only then did master and disciples remember what Wukong had done against monsters before.
At Sha Seng’s request, Bajie went alone to Mount Huaguo and after much goading talked Wukong round; the two went back to Baoxiang, rescued Tang Sanzang, and the party packed and set out west again.