Indian filmmaker Tabrez Noorani has previously worked as a line producer on films like Zero Dark Thirty, Life of Pi and Slumdog Millionaire. His feature debut Love Sonia is a gritty story of the sex trade in India – a globe-trotting journey that, for all its flaws, tugs hard at the heartstrings.

Beginning in a rural village, it's the tale of two sisters: Preeti (Riya Sisodiya) and Sonia (Mrunal Thakur). Weighed down by huge debts, out of sheer desperation their farmer father sells Preeti to the local landlord, who sends her to Mumbai to work in the sex trade. Sonia, under the naïve belief that her sister has gone to find work, begs the nefarious landlord to send her too. Before long, Sonia is trapped in a brothel, run by Manoj Bajpayee's seedy trafficker. Here she meets the unhinged Rashmi (Freida Pinto), but all she really wants is to find her sister. Almost everyone seems corrupt and connected to this repellent network, where a girl's virginity will fetch a high price from customers. Needless to say, Sonia falls into that category.

Undoubtedly, Noorani's intentions are noble, depicting the desperate plight of trafficking victims in India, and beyond, although the narrative is clunky at best. Demonstrating the worldwide nature of this business, Sonia is shipped off to Hong Kong and then Los Angeles – where both Mark Duplass and Demi Moore pop up in cameos.

There's a lot that's frustrating about Love Sonia, particularly the careless script; a big deal is made of Duplass's character presenting Sonia with a phone, for example, but it's never used. Yet full marks to Thakur, who gives a full-blooded performance as a young, innocent woman confronted with the very real cruelties of the world. Her story will leave you both sad and angry.

Selected release from Fri 25 Jan.