In the Museum of Australia there is a room dedicated to the history of 'integration' between colonialists and Aborigines. Along the walls are a timeline of all attempts undertaken across the centuries and the devastating impact they have had on the indigenous population. The history of Aborigines, as is the case with all native tribes who felt the destructive power of the West, is an unhappy one. A drama like Sweet Country, one that focuses on this, will always be a difficult watch, but a necessary one.

An act of violence propels Sweet Country into two pursuits. First is the search for Sam, an Aborigine who defended himself against a drunk racist but ended up taking a life. This takes a band of settlers across the Australian outback and into tribal territory. The second half is a pursuit for justice for Sam in a hostile environment. It is this that causes the film to linger long after the credits have rolled.

Director Warwick Thornton has spent his career exploring stories of Aboriginal culture, and Sweet Country may be his most accomplished film to date. The film is hauntingly beautiful, with the vistas of Australia a starkly contrasting backdrop to the bigotry that takes place there. I particularly admired Thornton's trick of giving the audience brief flashforwards during proceedings, the meaning of which are only revealed when the film catches up with them. It gives the film a prickly tension and draws the audience further and further into an already gripping narrative, right up until the film's devastating climax.

Sweet Country is expertly acted, with particular standouts being Hamilton Morris as Sam and Natassia Gorey-Furber as his wife (all Aborigine actors make their debut with this film). Morris has an understated quality, achieving a far greater impact with the little he allows us to see of the inner workings of Sam; while Gorey-Furber is heartbreaking as his loyal wife who must go through an unspoken horror. It is also worth noting that Sam Neill is, as expected, wonderful; even managing to bring a moment of levity in a very downbeat film.

This is less a Western and closer to a frontier film. It finds time to explore both the beauty of the characters' surroundings, and the limitations it places upon them. The film is a tad overstretched but has a brutal power, particularly in the final moments, which act like an emotional kneecapping for the audience. I was left stunned by Sweet Country, and I can't stress enough how much this is a must-see movie.

This is a London Film Festival preview and Sweet Country will be released at a later date.