The story begins in the third year after the end of "True Learning". Tang Monk was named the Sandalwood Buddha of Merit, Wukong was the Fighting Victory Buddha, Bajie was the Messenger of the Pure Altar, and Sha Monk was the Golden Arhat.
But - strange "memory cracks" began to appear in the three realms.
Some people remember that countless monsters died on the way to seek scriptures, some remember that the monsters were all included; some remember that Sun Wukong killed the six-eared macaque, and some remember that the six-eared macaque is the real Sun Wukong. The chaos of memory spreads across the three realms, including Heaven, Lingshan, and the Underworld. No one is spared.
The truth is: they never learned the lesson.
Everything they experienced was an infinite loop of cause and effect experiments written by a "being" that transcended the three realms.