Vilouna Phetmany in Dearest Sister. Photo courtesy of Bangkok Asean Film Festival

In this Lao film, a nearly-blind woman is visited by ghosts that come to tell her winning lottery numbers. Her young caretaker, a girl from the countryside, takes advantage of her mistress' impairment and cashes in on the phantoms' fortunetelling, scoring win after win. On paper, it all sounds preposterous. Ghosts that give out lotto jackpots? How superstitious! How Southeast Asia! But don't be mistaken: you should go and watch Nong Hak (Dearest Sister), a well-made Lao production that spins the supernatural premise into class critique and psychological horror, ripe with atmospheric suspense. In fact, this is simply a better film in terms of script and technical standards than many Thai flicks released each year.

The director is Mattie Do, an American Lao who grew up in California but who maintains a relationship with her ancestors' homeland (she speaks Lao as fluently as she does English). Trained as a ballet dancer, Mattie started making film about four years ago without any formal movie education. Dearest Sister is her second movie, written by Christopher Larsen and shot in Vientiane. Her first feature is also a horror story, called Chantaly, and her next one, she told me last month, will be a Lao sci-fi.

Dearest Sister puts two women in a haunted house, basically, and they turn out to be each other's scariest ghost. Nok (Amphaiphun Phimmapunya) is sent from a rural area to live in the capital with Ana (Vilouna Phetmany), a family relative who has moved up the social hierarchy after marrying a Western expat. Initially anxious with the young girl, the haughty, visually-impaired Ana warms to Nok after an episode with ghostly shadows that appear out of nowhere.

When the apparitions visit her, Ana falls in a trance and mutters random numbers -- it's not that random, however, as every Lao and Thai lotto fan knows. Nok starts buying lottery tickets and as Ana keeps saying jumbled figures, the girl keeps winning.

Money stashed under pillow, Nok is transformed. She gets to taste the life of those who have cash in a country where most people don't, the life that Ana has lived when she hangs out with friends at cafés that served fancy cappuccinos. But greed, jealousy and paranoia set in. Tensions between the two women rise, naturally, and here I shouldn't tell you more.

A blind woman who sees ghosts is not unprecedented -- it's straight out of The Eye, a Hong Kong-Thai horror hit from the 2000s. Dearest Sister also feels stagy at times, with persistent close-ups meant to convey claustrophobia. But here's a suspense story that keeps you with it until the end, while the encounter between the two women is fraught with cultural symbolism: rural vs city, superstition vs science (can an eye doctor in Bangkok cure Ana?), local belief vs international seduction (all those expats in Ana's circle). The film was released in the US, but it's Thai viewers who'll connect with the story's cultural details and social particulars. In many ways we could imagine this being made as a Thai film.

The two female characters are the film's central dynamics. Ana is cold and imperious because, as a poor girl who's no longer poor, she has to play her new part well. Nok meanwhile is spontaneous and street-smart; we're not quite sure if she's a good or bad person, if she's just exploiting her luck or actually corrupted by the city. And if the film seems to ride on the archetypal perception of female fury and suspicion, the two actresses, Vilouna and Amphaiphun, make it real and convincing -- something we didn't expect from what's at heart a horror film.

Nong Hak (Dearest Sister) Starring Amphaiphun Phimmapunya, Vilouna Phetmany Directed by Mattie Do In Lao with Thai and English subtitles at selected cinemas