As the curtain of time rises, a world 500 years beyond the imprisonment of Sun Wukong (Aaron Kwok) under the immense Five Fingers Mountain is unveiled. Enter Tang Sanzang (Feng Shaofeng), a novice Buddhist monk on a challenging pilgrimage to the Thunder Monastery in India, fueled by an intense yearning to gather the sacred Buddhist scriptures. However, unbeknownst to him, his peaceful expedition is on the verge of being dramatically altered, as cosmic forces pivot his fate.
By a twist of destiny, Tang Sanzang's journey tangles with a fierce tiger, compelling him to liberate the Monkey King from his ancient bonds. As Sun Wukong springs to life, he finds himself encumbered by an enchanted circlet, forged by the compassionate Bodhisattva Guanyin, which inflicts a painful penalty each time Tang Sanzang utters a particular sutra during their shared adventure.
Soon, this engaging duo is joined by Zhu Bajie (Xiaoshenyang), a gluttonous pig demon possessed by insatiable lust, and Sha Wujing (Him Law), an ethereal monk imbued with mystical energy. As they traverse the perilous terrain, Sun Wukong's unquenchable thirst for excitement juxtaposes with Tang Sanzang's staunch commitment to their spiritual quest, leading them into a whirlwind of exhilarating confrontations.
Their trek takes an ambitious turn when Wukong confronts an imposing dragon, scales shimmering like polished jewels in sunlight. With his signature bravado, he triumphed over the beast and, using his extraordinary abilities, transforms it into a magnificent steed, ready to accompany him on the perilous adventures that lie ahead.
Venturing into the Yun Hai Xi Kingdom, an unnerving air of dread greets them—a land consumed by the voracious appetite of the White Bone Demon ([Gong Li]). Her relentless craving for human flesh is fueled by her desire to defy death and elude the Wheel of Reincarnation. Obsessed with Sanzang, she believes that consuming him would break her cycle of rebirth and grant her eternal demonic existence.
Disguised as a kindly old woman, she lures the group into a secluded cottage deep in the woods. Utilizing Wukong's trusting nature as a weapon, she cunningly blinds him to her true intentions before her minions, masquerading as everyday women, ensnare Wukong, Bajie, and Wujing into performing trivial household tasks. Amidst her deceptive storytelling of her tragic past, Tang Sanzang unwittingly becomes the target of her deadly intentions. He intervenes just in time, but the crafty demoness manages to escape, leaving behind the cadaver of the elderly woman.
Following this harrowing encounter, the weary group grapples with disbelief, shackling Wukong with the label of cold-blooded murderer for eliminating creatures he believed to be demons. Seizing this moment of confusion, Sanzang disciplines Wukong through his sutra, intensifying the agony of the circlet around the Monkey King's head.
Determined to face the aftermath, Sanzang climbs a mountain to find Wukong, who broods in solitude. In a touching moment of reflection, Sanzang shares a revelation about their similar trait—their unwavering trust in the evidence of their own eyes—suggesting that this very trait has woven their fates together and is essential for untangling the chaos they face.
Upon entering the grand capital of the kingdom, they are welcomed with a lavish banquet from the King (Fei Xiang), who pleads for Sanzang to rid his kingdom of a malevolent spirit. Suddenly, Lady White materializes, her eyes laser-focused on the monk. Sensing her nefarious ambitions, Sanzang opts for the path of enlightenment instead, aiming to guide the lady towards redemption. Yet as Lady White attempts to convince Wukong to turn Sanzang over to her, a fierce battle erupts, plunging the banquet into chaos.
Amidst the turmoil, the King's guards apprehend Sanzang, unearthing a shocking truth: the King has been engaging in child abduction and slaughter to quench his own mysterious affliction through their blood. His attempts to eliminate Sanzang are thwarted only by the timely arrival of Wukong, who saves the monk and the remaining innocent children from being claimed by their impending doom.
Once the dust of chaos settles, the group is celebrated as heroes for their valor. Yet, a haunting realization dawns upon the keen eyes of Wukong—the very mother and child approaching Sanzang are pawns in the scheming grasp of Lady White. Enraged and betrayed, Tang expels Wukong from their group. This unsettling turn of events soon leads to Sanzang being abducted once more by the demoness he aimed to exorcise.
In the sinister depths of the White Bone Demon's domain, a daunting ultimatum looms over Sanzang: persuade her to renounce her malevolence and walk the path of enlightenment or face his own demise. As he hears her harrowing tale—one he already knows—hope appears to be dwindling. Just as despair threatens to engulf him, Wukong bursts onto the scene accompanied by Bajie and Wujing, and an epic showdown ensues against the White Bone Demon and her fiendish minions.
Emerging victorious after a fierce battle, Wukong delivers a lethal blow to the demoness, leaving her defeated and gravely injured. As the Buddha descends from the celestial realms to claim her soul, Sanzang implores divine mercy for the fallen demoness. Relenting, the Buddha places the burden of redemption upon Sanzang, whose path involves profound sacrifice.
Heavy-hearted, Sanzang pleads with the demoness to embrace remorse and join the Wheel of Reincarnation, yet she adamantly refuses, preferring to become a tainted soul within Sanzang's being. As Wukong grapples with the weight of this moment, inspired by Sanzang's message of leading by example, he readies to deliver the final blow.
In a moment steeped in destiny, Sanzang's spirit transforms him into a statue, embodying his unwavering commitment to his quest for enlightenment. Just before the profound change, he whispers to Wukong a promise of loyalty in their potential next life.
Time marches on, and as Wukong and his steadfast companions progress toward the Thunder Monastery, he carries Sanzang's statue on his back. Above them, the watchful gaze of Guanyin sheds a single tear from her mystical vase, which falls to earth and reveals a hint of Sanzang's eventual rebirth, signifying that their journey, rife with trials and tribulations, is far from over.
