A few minutes into Molla Sagar's dark, hallucinatory new film The River Titash, I started noticing the words on screen. I noticed them because, like the non-Bengali visitors to Chobi Mela IX, I also needed the subtitles. But isn't the film recorded in Bangladesh; aren't they speaking Bangla? What is happening here? There are many such moments in Sagar's work, where the shock of recognition illustrates how little you know of your own country. The protagonists of Titash are the historic Malo river community of Malopara, and their language is a hybrid of Bangla, Brahmanbaria and Comilla anchalik bhasha, and the Malo adivasi language. It is so intensely hybridised that my eyes kept turning to subtitles for rescue, a stranger in my own land.

Since the first encounter with Sagar's ghostly films a decade ago, his work has always brought me back to who I am not. Through immersive deep dives into rural and riverine Bangladesh, his films remind me that I am a city boy, who knew only the intensely urbanised Dhanmondi lake as a "water body." Like many others in Dhaka, we lost our ancestral homes and didn't have a gram Bangla to return to. In contrast to the romanticised aesthetic of gram in NGO discourse, Sagar's films are loving and unsentimental. His people do not live in a space of pity; they continue daily struggles, you are welcome to run along and try to catch up.

Molla Sagar's Jhor Jaillya - Natives of Tornado

In a prolific body of films, Sagar has traversed all corners of Bangladesh– People's Jute Mill in Khalishpur (Siren), Coal mine protests in Phulbari (Doodh Koila), Sundarban to Teknaf coastal areas (Natives of Tornado), Sunamganj (Cholo Mon Natok Dekhte Jai), Mongla port (Baniasanta), Netrokona (Dream), Bhola (Harmony of Dream), Buriganga (Gonga Buri), and Dhaka (Warmth quivering in blood). His subjects are always the defiant ones, including his last film Dadu, about a recently departed Sadhu of the Fakir ghorana. Until his death, Dadu was a permanent presence, and inspiration to students, at Charu Kala. He turned down a job offer by Zainul Abedin in the 1960s, but made the campus his home at the Shilpacharya's request.

In contrast to my own suffocating city childhood, Molla Sagar grew up in the syncretic locality of Bagerhat, on the banks of a Bhairav river which has recently dried into a skeleton. Much of Sagar's work is an archeology of our dying civilisation, choking on a tide of destructive neoliberal "development." Like several other artists I have been tracing, Sagar also attended Dhaka University's Charu Kala department (in graphic design), during the period of experimentation of the 1990s. By then, his affinity was already strongly for the video form. Since Charu Kala has yet to add photography or video to its curriculum, Sagar eventually left the campus and sought inspiration outside its walls. In addition to the gram he knew so well, he joined, and was formed by, the intense organising of the Shamsunnahar Hall movement, the Happy bus accident movement, the Humayun Azad movement, the Phulbari Andolon, and finally the Baul Andolon (Banglar Shanskriti Andolon) of 2007-2008 during which I first marched alongside him.

In this latest project The River Titash, he has remixed scenes from Ritwik Ghatak's Titash Ekti Nodir Naam (1973) with Sagar's own return to the home of Adwaita Mallabarman, author of the original novel. Over the last year, Sagar organised floating exhibitions of Ghatak's film along the original Titash river (a technique of bringing mobile cinema to the people also practiced by Tareque and Catherine Masud for Muktir Gaan, as well as, in the case of photography, by Chobi Mela). Watching the dramatic splicing of black and white scenes from Ghatak's Titash with Sagar's contemporary Titash, I marveled that an iconic work of 1973 (the first Indian-directed film in post-1971 Bangladesh) took this many years to enter the remix. Perhaps we were all looking elsewhere, at bright lights, while Sagar stayed focused on the village, the river, and its peoples.

Adwaita Mallabarman was born within the Malo community of Malopara in Brahmanbaria, but moved to pre-partition Kolkata to become assistant editor for Navashakti. He also went on to work at Azad and Mohammadi, the latter closing when its' Muslim editor took the Pakistan "option." Throughout this period, and also later while at Desh and Anandabazar, Mallabarman donated a part of his salary back to Malopara to educate children (one of the songs in Sagar's film mournfully wishes Mallabarman would return to help the Malos again today).

I mentioned earlier that Sagar grew up on the river Bhairav, attended and then left Charu Kala, and found his inspiration through movement struggles. The result is a cinematic language that is sui generis, with a unique rhythm rising wholly formed from this soil. Film critics often compared Tareque Masud's work to Satyajit Ray and Abbas Kiarostami; but you would be hard pressed to find such clear precedents for Sagar's style. From his earlier premieres in 2007, I noticed how he used irregular editing rhythms, unexpected cuts, extreme closeups, animal and water level point of view, a moving back and forth between night and broad daylight, and slow motion– all coming together to build film as visual poetry. Another Bangladeshi filmmaker who has worked with riverine subjects is Kamar Ahmed Saimon, whose Shunte Ki Pao? brought us into close proximity with villagers living on the edge of climate apocalypse. But while Saimon's visuals are gorgeously composed, bearing some of the influence of his mentor Tareque Masud, Sagar's form is more jagged and unexpected.

Sagar shoots over many years, and accumulates thousands of hours of footage. Assembled films are a crazy melange of different cameras, codecs, resolution, color balance, and tempo– and yet it all comes together to form a path, rather than only collage. His work is often mistaken for simply ethnographic documentary, but is actually playing with conventions continuously. Three moments from the latest Titash will illustrate his approach to cinema. In one sequence, a Malo boy tenderly steps into the river and puts water to his face. As the shots cut back and forth, you expect the usual innocence and nature sequence. Only in the last jump cut do we see the boy run his fingers around his ear for a second. In that split second, which leaves before you can register, you realise that this may be a Malo family that has converted to Islam. Considering the complex relationship of our indigenous peoples to dominant forms (mainly Christianity and Islam), this small moment hints at volumes.

In another scene, a man is crouched down and speaking of the way Muslims have taken over the fishing business. In an earlier night scene we encountered an almost blind man who asks Sagar what kind of new nets are these that catch not only fish but also their eggs, destroying the delicate life cycle ("Can there be tree without seeds?"). Now this younger man speaks of the way Bengali Muslims have taken over Malo livelihoods, assisted by government regulations that ignore indigenous property rights (as in Chittagong Hill Tracts). "First you took Muslim peoples are partners!!" interjects a voice, and the camera rolls up to take in two more listeners, both Muslim fishermen. In this moment, a wall is broken as you realise that the conversation you thought was an intimate confidence is actually in full sight of those being critiqued. Sagar's films are full of vertiginous moments like this, snaking in and out of the same film. A group of Malo sit in darkness, and one lights a cigarette– its' red tip is the only light in absolute darkness. Later, a wavy slow motion camera follows a boy doing an upside down headstand on a boat; as your eyes fix on the lit cigarette, you have returned to that first scene, completing a subtle sub-cycle within the film.

The work of Molla Sagar has remained largely undiscovered by the mainstream cinema of Bangladesh. Sagar does not focus on showing his work in galleries or cinema halls, preferring instead to tour villages with his work, release DVDs to the mass market, and edit an online cultural magazine Shap Ludu (shapludu.com). At Dhaka's cultural events, he is often absent, already working on his next film, and the next. A small group of us have been following him for a decade, and his work has been breaking our hearts for that long. If you care for the future of film, go to YouTube, get hold of a DVD, or organise a public screening. The beginnings of the new Bangladeshi cinema you were wishing for is already here.

The writer is a historian who uses essays, films, and mixed media to trace the history of Bangladesh after 1971.