The movie centers on the Buddhist idea of Saṃsāra—the endless cycle of birth, death, and rebirth—and uses it to tell a sprawling tale of two snake demons weaving themselves into human life, and of a monk who must confront the consequences of his actions.
A Buddhist monk named Fat-hoi [Vincent Zhao Wenzhuo] has trained for twenty years to banish demons from the Human World. He is stringent in his belief that non-human beings should not seek spiritual growth, and when he encounters a spider demon masquerading as a Buddhist priest, he captures it with a cool certainty. The spider demon pleads for mercy, claiming centuries of spiritual refining to achieve reincarnation, but Fat-hoi clamps a magical cauldron around it and leaves it beneath a gazebo. Only when the beads on the demon’s body begin to glow does Fat-hoi sense that he may have misread a path to enlightenment and that his interference might have complicated a worthy journey.
A sudden storm drives Fat-hoi into the forest, where he confronts two Snake spirits and nearly destroys them. He soon realizes they were not malevolent by instinct; they were safeguarding a mortal woman who is giving birth, and in a rare moment of compassion he releases them. The two sisters—White Snake [Joey Wong Cho-Yin] and Green Snake [Maggie Cheung]—have trained across centuries to take human form, and they quickly reshape their destiny. White Snake, the elder and more disciplined of the pair, falls in love with a local scholar, Hsui Xien [Wu Hsing-guo], and dreams of starting a family and continuing her journey toward human reincarnation. Green Snake, younger and more impulsive, yearns for affection and explores the edges of sensuous life, often pushing the boundaries of their new world.
The sisters establish a magical house and begin a thriving medical practice in town. Their presence is tempered by a recurring visit from a buffoonish Taoist, whom Green Snake eventually leaves in charge of the household. Because White Snake’s beauty and grace attract attention, Hsui Xien’s reputation—once the village’s most steadfast scholar—begins to waver as he is drawn into their circle.
When a flood devastates the village, White Snake and Green Snake rise to help, aided once again by Fat-hoi, whom they vaguely remember from the forest. After the waters recede, the sisters’ standing in the community deepens, but Green Snake grows increasingly envious of White Snake’s bond with Hsui Xien. She tests boundaries by using Hsui Xien as an experiment, and although White Snake dismisses these intrusions, the tension between the sisters begins to strain their relationship.
As the Dragon Boat Festival approaches, the sisters face a critical test. White Snake urges Green Snake to leave the village, knowing that the magical wine—Xionghuang—reveals true forms on this day and could expose Green Snake. Green Snake resents this division but obeys. That night, White Snake tries to force Hsui Xien to drink with her, but he secretly pours the wine into the pond where Green Snake hides; the revelation of Green Snake’s true form shocks him, and he dies of astonishment. The encounter is interrupted by the returning Taoist and his apprentices, whom White Snake quickly overpowers.
White Snake travels to Kwun Lun Mountain to obtain the Lin-Chi Herb to resurrect Hsui Xien, a quest that Green Snake joins out of guilt after her earlier actions. They succeed in bringing Hsui Xien back to life, but Fat-hoi follows and confronts them. White Snake leaves Green Snake to deal with Fat-hoi while she rekindles her relationship with Hsui Xien, and the two seem to be moving toward happiness once more.
Fat-hoi, driven by doubt about human sensuality, accepts Green Snake’s temptation in a final attempt to measure his own resolve. When Green Snake tries to seduce him, he loses the inner contest, and Green Snake returns to White Snake. She reveals she is pregnant, and the burden of this truth drives a wedge between the sisters, pushing Green Snake to depart.
Hsui Xien confronts Fat-hoi, and the monk offers him a protective bead set to shield him from evil spirits. Rather than accept the beads, Hsui Xien tosses them into the river and confronts the two sisters at home. Fat-hoi, determined to restore balance, abducts Hsui Xien to his Peaceful Land temple perched on an island peak for “restoration.” White Snake pleads for the return of her husband, but Fat-hoi refuses, sparking a deadly clash. Green Snake joins the struggle, triggering a flood that the monk tries to avert by lifting the temple into the air; when that fails, he attempts to smother the sisters with his surplice, but they prevail.
White Snake goes into labor as the flood advances, and Fat-hoi withdraws his protection, allowing Green Snake to reach the temple and rescue Hsui Xien. In the chaos, White Snake is crushed when the temple is destroyed. Green Snake manages to save Hsui Xien, but she kills him so that he can be with her sister in the afterlife. Fat-hoi, now confronted with the consequences of his own role in the tragedy, is left to face the future alone, holding the baby that remains as a fragile reminder of the complex, intertwined fates that define this tale of love, power, and the endless reach of samsara.
