Set in 1938 in the twilight of colonial India, "Water" focuses on a group of women condemned by Hindu law to spend the rest of their lives in an institution, or ashram, on the banks of the Ganges because they are widows. While the devout Shakuntula (Seema Biswas) spends her days assisting a local holy man, the limpid-eyed Kalyani (Lisa Ray) — the only widow whose head has not been shaved — is forced into prostitution by the ashram's domineering housemother. Employing a sly eunuch as go-between, the housemother sells Kalyani's services to a wealthy Brahmin on the other side of the river.

The arrival of Chuyia (Sarala), a bewildered 8-year-old whose husband has just died, creates turmoil in the ashram. The child's impudence and high spirits encourage Shakuntula to question her fidelity to a religion that turns widows into penniless outcasts. Kalyani too is inspired to rebellion and begins a love affair with Narayan (the Bollywood star John Abraham), a handsome law student on fire with Gandhian idealism. But when Narayan's wealthy parents are informed of the relationship, the couple's defiance of religious and cultural taboos is an invitation to tragedy.

Written and directed by Deepa Mehta, "Water" is an exquisite film about the institutionalized oppression of an entire class of women and the way patriarchal imperatives inform religious belief. Serene on the surface yet roiling underneath, the film neatly parallels the plight of widows under Hindu fundamentalism to that of India under British colonialism. Though Gandhi and his followers are an insistent background presence, the movie is never didactic, trusting the simple rhythms of the women's lives to tell their story.

Mustering a whole spectrum of luminous blues and greens, Mehta and her cinematographer, Giles Nuttgens, paint a vibrant world of lambent light and indigo shade. The lushness and texture of the ashram's surroundings are in stark contrast to the widows' unflattering white robes, which hang from their bodies like dirty bandages; but here even images of deprivation gleam like gold. Never has the Ganges (played here by a river in Sri Lanka) looked so inviting.

Shifting between romantic melodrama and spiritual inquiry, "Water" flows with the simplicity of a fairy tale. The lovers' struggle may be the heart of the film, but Shakuntula's awakening is its soul. In the triumphant and moving final scene, her selfless act of bravery offers hope to Chuyia and India alike.

"Water" is rated PG-13. It contains a suggestion of prostitution and some brief drug use. Running time: 114 minutes.