Spoiler alert: the mattress ends up in a swamp, and the two men with it. We meet the pair amid the clangour of cranes. Surrounded by thick green foliage, they lie on the mattress, shirtless, in black shorts and boots. They glug bottled lager and discuss the state of the world. But not for long: soon they must move the mattress. “Apparently it mustn’t stay here,” says one. This is the only explanation we’re given.

Joanna Rajkowska’s film, Two Men and a Mattress (2017), was commissioned by Arts Territory within the framework of The Illusion of Return, an ongoing series of projects exploring the subjects of migration, home and belonging. The film was conceived, at least initially, as a response to Brexit. But the rise of the right in Poland and Hungary, the US and Brazil demonstrates, once again, that nationalism has always been a transnational phenomenon.

Joanna Rajkowska is best known for public art projects that have occasionally proved controversial. On Warsaw’s Jerusalem Avenue, she erected a fifteen-metre-high artificial palm tree (Greetings from Jerusalem Avenue, 2002-ongoing) as a link between the landscapes of Warsaw and Palestine and a reminder, according to an accompanying text, of “the void left by the absence of the Jewish community in Poland”. In Poznań, Poland, she proposed converting a disused chimney into minaret (Minaret, 2009). In Peterborough, UK, she proposed a fake archaeological dig containing a replica of a 3,500-year-old infant foetus (The Peterborough Child, 2012). These latter two projects generated significant public debate and were never realised publicly.

Such public controversies stem not from a desire to shock but from the artist’s genius for locating the wounds that lie raw beneath the bandages applied by society, and her bravery in poking at them. In seemingly simple gestures, Rajkowska uncovers layers of trauma, unspoken histories, a society’s desire to remember or its desire to forget. The artist’s research process is laid bare in her book, Where the Beast is Buried (Zero Books, 2013), in which she writes heartbreakingly, for example, of the loss of life, language and “the rich, juicy life woven between cultures” that characterised Poland prior to the Nazi invasion.

“An artist is a seismograph,” writes Rajkowska in one of the six interviews that concludes Where the Beast is Buried. “And a shaman if she can do it.” Five years on, this still stands as a kind of artistic manifesto. As the seismograph, Rajkowska traces the ripples of history, maps the psyche of a place. As a shaman, the artist performs vital societal functions – listening, curing, transforming. To me, this seems like something that takes place from the fringes of that society. But Rajkowska disagrees: “From very much inside of it,” she says. “From its intestines.” Via Skype, she elaborates on the role of the artist: “I feel like I have a mission,” she tells me, “to articulate things that are not well received in public space: weakness, the disintegration of the body, the biology of our existence.”

Two Men and a Mattress started with Brexit. In particular, Rajkowska was interested in the sense of inevitability that has accompanied much discussion on the subject. “The people” have spoken: now it is down to the politicians and civil servants to enact their will. As 19^th-century French politician, Alexandre Auguste Ledru-Rollin is said to have announced: “There go the people. I must follow them, for I am their leader.” Incidentally, it is worth noting that while 17.4 million people did indeed vote to leave the European Union, compared to 16.1 million who voted to remain, a whopping 31 million did not vote at all. Any debate therefore that seeks to pit “the people” against “the elite” is nonsense from the beginning.

“I was trying to grasp this sense of inevitability,” Rajkowska tells me. “It just rolls downhill like the laws of gravity.” While the recent People’s March in London made the same error as many of those who are in favour of Brexit (that of claiming to speak on behalf of a muted majority), it did at least demonstrate a desire to fight against the sense of inevitability that Rajkowska identifies. In Two Men and a Mattress, the two shirtless British men struggle to carry the mattress through dense Polish forest on a hot summer’s day. No reason is given for their action. Instead, one of the men says simply: “There is a kind of inevitability, once you start…” Like all self-fulfilling prophesies, they think it’s true so they make it true.

The swamp was perhaps inevitable in another way too: dirty water is a recurring presence in Rajkowska’s work. “It is so irritating that we see water only as this life-giving power,” she says. “I don’t like water as a symbol of purity. I don’t like symbols: symbols detach things from their material existence. They structure things on a higher level, invest meanings in them, turn them into abstractions. I always try to take things down.” This desire is clear from numerous previous projects: Rajkowska has, for example, taken a sculpture of a bishop and submerged it near a sewage outlet in a Kraków river (Aquarius, 2009); she has proposed the transformation of Schloßplatz, a flat grass square in Berlin, into a prehistoric marsh (Sumpfstadt/Swamptown, 2012); and she has proposed the re-flooding of an ex-industrial area of Sheffield (Waterfall, 2013). Once again, several of these projects (including Sumpfstadt and Waterfall) have remained unrealised. It’s telling, if unsurprising: the weaknesses, the biological limitations, the simple fact of mortality that Rajkowska probes in these works are precisely those things that urban power structures would, for the most part, rather conceal.

But Rajkowska’s water is not only muddy. One of her key works (Oxygenator 2007) temporarily transformed Warsaw’s Grzybowski Square, once part of the city’s ghetto, now surrounded by high-rise flats. She installed a circular pond equipped with ozonating equipment, a fog machine and surrounded by greenery and seating. Rajkowska tells me that this as one of her most successful public works. “I want people to have an experience, a deep sensual experience,” she explains. “With Oxygenator I saw people with their eyes closed, just breathing. They didn’t talk, they were just completely at ease and overwhelmed. That’s where I would like the experience of art in general to be.”

And yet, despite this apparent simplicity, Rajkowska also complicates any simple understanding of cleanliness. An early work (Let Me Wash Your Hands 1994) saw the artist wash the hands of visitors to New York’s Sauce Place Gallery with iodine. Iodine “cleans and purifies, prevents infection, decay and the growth of microorganisms,” reads an accompanying text, “but it will never make your hands or my mind clean.” In Two Men and a Mattress, the men seem surprisingly happy sitting in the swamp. “It’s a lot cooler than it was up there,” one of them observes as the mattress sinks beneath the surface of the water, and the camera with it.

Two Men and a Mattress has been compared to two much earlier films (although Rajkowska only became aware of the links with her own work after completing the edit): Stefan and Franciszka Themerson’s The Adventures of a Good Citizen (1937) and Roman Polanski’s Two Men and a Wardrobe (1958). Where the Themersons’ film is formally characterised by a madcap inventiveness, Polanski’s is more grimly violent. Both depict individuals behaving unconventionally and society’s intolerant response. It is hard to watch these films in the UK today and not think of Theresa May’s abhorrent “hostile environment” policy.

In Rajkowska’s film the environment is a natural one (a Polish forest) rather than an urban or social one. And it is unpleasant rather than openly or violently hostile: tree branches scratch the men’s bare white torsos as they struggle through the foliage and the heat. The film was shot in a rural district near Toruń in northern Poland, where Rajokowska and her family were living temporarily. That experience confronted Rajkowska with the difficulties of rural life. “It’s probably a typical experience for someone who didn’t grow up in a forest or on the outskirts of a village,” she says, “but I came to the conclusion that we really do not belong to this world. In the process of detaching ourselves from the natural environment, in building dwellings, insulating them and so on, we’ve created a bubble, but we are part of the bubble more than we are part of the environment.”

Despite Rajkowska’s antipathy towards the symbolic, I can’t help but see the mattress itself in this light. It is a mass-produced object of comfort: yet another material layer between our bodies and the ground. Designed exclusively for interior use, a mattress seems so sad and so absurd outside in the city streets or in a forest or a swamp. And yet how often they are seen outside: carelessly dumped by a private citizen, yet to be collected by state-employed waste management workers. The attitude of individuals, the reach of the state: both dictate how long each mattress will lie outside – at once an eyesore and a temporary home for those that might have none of their own. Soon it will be buried in landfill, where it will float to the top and lie there for a hundred years.

Perhaps the sadness I feel is not misplaced. Cranes are migratory birds, and that clanging sound, Rajkowska tells me, is the noise they make when they depart in the autumn. She could hear them when living in the village near Toruń. “It is a farewell sound,” she says. In the film, they drown out the halting notes of Ode to Joy, from Beethoven’s Ninth Symphony, and, significantly, the anthem of the European Union. “To me this film was always about the suicidal decline of human civilisation in general,” explains Rajkowska, “paradoxically propelled by the enlightened idea of progress.”

So what to do? Torn between hope and despair, Rajkowska articulates a dichotomy at the heart of much environmental thinking, which struggles to conceive of a home for humans within a natural world that could flourish together with us. As American environmental historian William Cronon has written in critique of the romantic desire for pristine wilderness: “if nature dies because we enter it, then the only way to save nature is to kill ourselves.”

For Rajkowska, the non-human natural environment is “not something that serves us, that helps us, that is created for us”. Instead, she elaborates: “It is just what it is. It has its rights, its procedures and, yes, we are part of it: each of us is a pile of bones, a body that cannot transcend its biological dimension. But at the same time we’re different. The fact that it is not for us is probably the most important thing. The natural world is not a botanical garden.”

Earlier this year, after meeting with Rajkowska in Warsaw, I visited Trafostation (2016), an outdoor installation that she made for Wrocław. Like Aquarius, Trafostation is one of Rajkowska’s more subtle works: a continuous wall of water falling down the side of a defunct transformer station from 1930, it is hardly visible as art at all. I got lost in a suburb before realising I had walked right past it. Algae coats the wall, birds flit in and out of the concrete structure, people look at me oddly as I stand and stare. In some ways this is a hugely depressing work: a reminder of a 1997 flood that devastated the city, a nod perhaps to the great floods that populated mythology, that will one day come again. This work is not for me, it is not for us. In Warsaw, Rajkowska described it as art for the non-human. But in acknowledging that, other feelings arise. I can stand and look and listen and think without ever assuming that my presence here is necessary. When I turn to leave, the water will continue to fall, the algae to grow – until the elaborate pumping mechanism stops working and the concrete finally crumbles to the ground. I feel powerless and it feels good. Trafostation is a human-made gift for a non-human world. It does not exclude the possibility of a human presence but it does not empower; instead it embraces with a strange cold warmth.

This perhaps is precisely the point. Rajkowska is highly critical of the rhetoric of empowerment that she sees across the political spectrum (“a masculine power, a very mechanical view of the world that always has to be possessed or controlled in some way”). This is something that her work is committed to fighting against, in its own way. “We’re totally, absolutely dependent in every way,” says Rajkowska. “I want to make people aware of this dependency. It may be completely utopian and impossible, but if we manage to raise up one generation of humans with a proper sensitivity towards everything else, towards the environment that actually hosts us and keeps us alive, then that could completely change the life of this planet.”