Water completes director Deepa Mehta’s controversial trilogy about life in India. Why controversial? Consider the subject:

Fire (1996) centered on a modern-day lesbian relationship between a desperate housewife and her sister-in-law. Earth (1998) chronicled Hindu-Muslim tensions during the 1947 partition of the filmmaker’s home country.

The final installment — delayed four years after protesters burned sets and successfully lobbied to have Mehta’s filming permits revoked — tells the moving story of widows living under 2,000-year-old Hindu law.

Shot in Sri Lanka, Water opens in 1938 as newly widowed Chuyia (Sarala) arrives at an ashram of similarly "afflicted" women.

She is only 8 years old.

Chuyia has three choices according to ancient laws: remain chaste for life, marry her former husband’s brother or burn herself alive.

The implications of her plight are largely lost on the little girl, who fidgets as any child would as her father shears off her blueblack mane — a signal of widowhood — then abandons her to a life of societal subjugation.

Much like Earth, the story takes place through the eyes of a young girl, although Mehta sometimes leaves the ashram to follow middle-aged Shakuntala (Seema Biswas) and 20-something Kalyani (Lisa Ray) — both of whom show tentative signs of revolt.

The rest of the predominantly female characters have resigned themselves to life under religious law — even as the forced prostitution of younger widows is deemed an acceptable means of survival.

One of the most heartbreaking moments of the film comes when Shakuntala observes that Chuyia is "getting used to this life."

As somber as the story might sound, Mehta injects occasional bursts of joy and humor into the lives of her characters, who take pleasure where they can find it.

A romance develops between the beautiful Kalyani and a young, aristocratic suitor (John Abraham), who espouses the radical thinking of Mahatma Gandhi. Shakuntala, meanwhile, begins to question the spiritual legitimacy of her beliefs.

Water edges toward melodrama as the subplots unfold and intertwine, coming to a head in the rousing, Hollywoodstyle finale. But Mehta, who immigrated to Canada in 1973, has earned the audience’s trust and admiration by that point.

"What if our conscience conflicts with our faith?" Shakuntala asks late in the film.

The query lingers with the viewer long after the closing credits. Which moral foundation would we alter? Which would we ignore? The women in Water ask these questions; some even try to answer them.

The results prove devastating and uplifting.

nchordas@dispatch.com