Theatre director Cavalli arrives to stage a production of Julius Caesar with hardened prisoners, auditioning them for their roles as we are told about their sentences. Many are inside for mafia crimes, and they take to this story about men of honour naturally, rehearsing in the prison's corridors and common spaces for six months before the big performance. And of course the lines between art and life begin to blur for these men.

Striano is riveting as Brutus, the conflicted man who in an effort to do the right thing turns on his best friend Caesar (Arcuri). He's a natural actor who delivers the modernised dialog with real intensity and physicality. Arcuri is also superb, often clad in a sheet to indicate Caesar's status as well as his fate. Other standouts include Rega as Cassius and Frasca as Mark Antony, who delivers his famous eulogy in the exercise yard while prisoners watch through their windows.

These touches add surprising emotion to the scenes, as does the decision to update the language and let the actors speak in their original dialects. As a result much of the tension in Shakespeare's play feels like it spills out into the prison itself, so the scripted non-play scenes have authenticity even if the dialog sometimes feels arch.

After a prologue showing the play's final scenes in lurid colour, the Tavianis shoot the entire rehearsal period in black and white, perhaps to highlight the documentary nature of the film. It's strikingly simple and looks terrific, although it might have worked better the other way round, as it concludes with the striking stage performance (in colour again) followed by the actors' anticlimactic return to everyday prison life. But it's a bold approach, and so intimate that it can't help but surprise us with our own reactions to both layers of the story.

Juan and Natalia (Jimenez Castro and Acevedo) have moved from the city to the countryside to get some fresh air and raise their two young children Eleazar and Rut (played by Reygadas' own children). Amid their dreams about how their life can be, they can't help but feel like outsiders in this rural landscape, surrounded by seasoned workers including handyman El Siete (Torres). And as they suffer from dangers both real and imagined, the family's life takes some surprising turns.

This is as good a stab at a narrative as you can make, based on implications in a procession of seemingly unrelated sequences, including a glowing red devil who sneaks into a house with his toolbox at night, an English school rugby match and a visit to a French sauna sex-club. Much of what we see feels eerily random, and yet there's a thematic thread running through it, as Reygadas explores this family's connection to society, nature, religion, economics and each other. Plus the local cows and horses and a number of pet dogs.

The film is shot in squared-off Academy ratio, which crops the frame tightly to the expressive faces, while Alexis Zabe's gorgeous cinematography captures the colours and textures of each setting. But clearly not everything is what it seems, as images are prismed around the edges as if we're looking through old glass at something we shouldn't be able to see. Again, what this means is anyone's guess, but every moment is seriously striking to look at.

Without an actual narrative, the film rolls along with no sense of structure or momentum, and yet we can feel the growing unease. Something dark is clearly on the way, hinted by moments of violence, tense dialog and snippets of the characters' back stories. Not that we could ever predict anything that happens or how things develop. But then, this isn't a rational plotline; Reygadas is saying something much deeper about what it is to be human. We may not quite know what he intended, but we do feel something primal.

Cesar (Tosar) is the concierge at a creaky apartment building, where he prowls through the hallways causing havoc for the privileged tenants he secretly despises. As his boss (Lasarte) looks for a reason to sack him, Cesar secretly torments an elderly woman (Martinez) and her two beloved dogs, then sets up mother-and-son cleaners (Fernandez and Morilla) to take the fall. And when a teen neighbour (Almeida) catches him, he brutally convinces her to keep quiet. But his biggest plan is for the sexy young Clara (Etura), whose boyfriend (San Juan) is away on business.

This is one of those thrillers that sustains a low-boil, refusing to give up its secrets but never letting us feel like the filmmakers are cheating us. It also never takes the easy road by trying to make us like the characters. Tosar plays Cesar unapologetically as a likeable, trusted friend who's actually up to something sinister. It doesn't matter that we never clearly understand his carefully orchestrated plan, which he outlines to his ill mother (Roset), but we know he has a reason. And the script hints that he has done this before.

In fact, the script is so packed with insinuation that every scene boggles the mind with possibilities. Each encounter promises something even more insidious than the last, with a new sense of victim and tormenter. Although no one seems terribly innocent. Even Clara is cleverly portrayed by Etura as an attractive woman who gets what she wants from everyone around her, so when things start to turn nasty she simply can't cope.

There are a few false notes, including the fact that Cesar continually eludes discovery. But the filmmakers constantly throw surprises at us, with situations that are squirm-inducingly perilous and encounters that start warmly before shifting into cruelty. And Balaguero directs in a silky style that combines Almodovar-esque characters with an almost haunted-house vibe. It's remarkably unsettling, mostly because we really shouldn't see hopefulness in the conclusion. But we do.

On the edge of Buenos Aires, a gigantic hospital construction project fell apart years ago, leaving the vast unfinished building as a white elephant. And this embarrassment is now the centre of a sprawling shantytown run by warring drug lords (Gatti and Varela). Then a group of priests move in to turn things around: inspirational leader Julian (Darin) brings in his Belgian friend Nicolas (Renier) to join the team, along with social worker Luciana (Gusman). But increasing violence puts them in danger, especially as they're caught between rioting people and heavily armed police.

The film opens with a series of scenes that show just how fragile Julian and Nicolas are, with horrific past events and physical issues that make their tenacity even more inspiring. Filmmaker Trapero sets deeply personal storytelling against the almost overwhelming size of the slum, using earthy doc-style filmmaking to keep everything raw and real. And all of the acting is visceral, with especially layered turns from the leads.

Darin brings a potent sense of Julian's refusal to give up mixed with his reluctant realism. Renier beautifully shows how Nicolas' haunting past leads to growing fearlessness. A long tracking shot following him into a the den of the beast is astonishing: "We want peace", he says, to which kingpin Varela replies, "That's a lot to ask for." And detailed side characters are played so vividly that we never feel like we're watching actors.

As the story builds to a massive confrontation between the church aid workers, the police and the gangs, the film is a series of nearly apocalyptic events. Sudden rainstorms flood the village. Bishops try to manipulate crowds with tales of miracles. The police raid with guns blazing. It's such a tough, messy, thoroughly authentic story that we can't help but be swept up in the escalating crisis. And along the way we are challenged to try to make a difference somewhere ourselves.