Watching High Ground, you can’t help but feel you’re witnessing something groundbreaking. Not only was it shot on location in Kakadu National Park and stunning East Arnhem Land on country that has never before been seen on film (in parts of protected Cannon Hill), but the story itself is one you won’t have learnt in school.

The film begins in 1919 in the remote vast plains of the Northern Territory where a ragtag bunch of former Australian soldiers have joined the police service and are attempting to keep order among the white settlers and nomadic Indigenous tribes. A botched police operation overseen by former sniper Travis (Simon Baker) sees one officer go rogue, resulting in a horrific massacre.

Travis is appalled by what he’s witnessed. He rescues a terrified boy, Gutjuk, and takes him to a nearby missionary camp where he is raised by the gentle Father Braddock (Ryan Corr) and his sister Claire (Caren Pistorius). Travis disappears, disgusted that the truth will be covered up, only to be brought back years later to hunt down Baywara, the leader of a “wild mob” of Indigenous warriors attacking and burning down local cattle stations in revenge for the massacre. Travis enlists Gutjuk, now 18 (newcomer Jacob Junior Nayinggul, a Gunbalanya man who had never acted before and who works as a ranger in East Arnhem Land), to help. But he’s just discovered Baywara is one of his few remaining blood relatives – his uncle.

Baker is best known for his Emmy and Golden Globe-nominated lead role in The Mentalist, and his award-winning directorial debut Breath (which he also starred in), an adaptation of writer Tim Winton’s novel of the same name. He was drawn to the film when he ran into director Stephen Maxwell Johnson while attending the annual Garma Festival of Indigenous culture in north-east Arnhem Land in 2017.

The character of Travis appealed to Baker; he has empathy but lacks any real understanding of Indigenous culture, history and connection to the land. He signed on alongside good friend Jack Thompson, who plays a police officer. Baker also respected that the script deals with a side of Australia’s history we’re not taught at school.

“I really liked the idea of seeing a story where Indigenous Australians were not portrayed as victims, [showing] that there was a resistance. The notion of never ceding sovereignty is a big one … they didn’t just say, ‘Sure, have what you want’, they tried to protect it and preserve their culture. They fought for it.”

High Ground is fictional but draws from truth. The film is co-produced by Witiyana Marika (who plays Grandfather Dharrpa in the film). Dharrpa is a calm, wise leader who seeks peaceful co-existence with the settlers. Marika is also the co-founder, alongside the late Dr M Yunupingu, of mega successful Indigenous band Yothu Yindi, whose song Treaty was the first rock song in an Indigenous Australian language to gain widespread attention. It also became Australia’s unofficial anthem of the reconciliation movement.

Marika has also generously shared deeply personal stories of his people’s past, including the 1930s massacre of his relatives.

“I wasn’t taught at school about the massacre, it was my father who taught me, and his uncle told him what happened to his mother nation in the 1930s. Every night as I was growing up my father used to tell that story.”

High Ground is a collaborative film shot in consultation with various traditional owners of the lands on which it was filmed. And many local Aboriginal people worked both behind and in front of the camera.

The seven-week shoot wasn’t without incident. “We had to cross [the East Alligator River] nearly every day to go to work. It’s a tidal crossing so you cross the causeway and there were crocs on either side of it,” says Baker.

“They were waiting, waiting for fresh meat!” adds Marika enthusiastically. “We had a croc walk through the set. It was a pretty wild experience, and the wet season was coming; some of the storms we had were unbelievable, they destroyed the set,” Baker says.

There are high hopes for High Ground, which has a broad national release. The senior cultural advisor on the film, Marika, hopes it represents a new way of working together – a “both-ways film, First Nations and Balanda (non-Indigenous)” – in sharing more truthful stories from our nation’s shameful past but also in finding a peaceful, united way forward.

“This pain [of our past], you’re not going to wash it away with water, it will wash away by your sweat, your love. That’s what my father told me,” says Marika. “You can dance it off, standing in mother earth, celebrating father sky. That’s the power, what he told me.

“I’d like to see the whole of Australia become one through unity and love. One nation, where all people reconcile and move forward.”

High Ground opens nationally on Thursday January 28, but some cinemas have previews from Tuesday January 26. Watch the trailer.