On the run after a failed heist, sisters Lisa and Claire (Lowe and Wells) steal a car belonging to sibling poets (Daniel and Cage), then assume their identities to hide out at a beat poetry retreat in the Welsh countryside. Lisa is determined to find a man, and sets her sights on the dishy-dopey Richard (Cullen), whose snobby girlfriend Louise (Robson) turns up later. As Gareth and Stacey (Elis and Patch) lead this small group on a three-day hiking trip, everyone is jostling for position, jealous of the attention anyone pays to anyone else.

The actors and filmmakers are making all of this up as they go, so the dialog is as freeform as the corny poetry these people are writing on the fly in an attempt to win a frankly unlikely prize of £11,000. Much of what's said is purely navel-gazing, which kind of makes it impossible to see these as real people with an inner life and back-story of their own. They're like characters from a comedy sketch: wacky, random and rather pathetic. And the funniest lines are non sequitors.

The actors are fine at creating these roles, even though all of them are utterly ridiculous. Lowe gives Lisa a kind of desperate charm, while Wells finds some underlying intelligence in the dithering Claire. Cullen is very likeable as nice-but-dim Richard, although it's impossible to see why Robson's needy diva Louise is so hung up on him. Meanwhile, Elis thankfully only rarely overplays Gareth's crush on Louise, but Patch's Stacey is left in the margins, so that subplot goes nowhere.

Frankly, none of the plotlines go anywhere, and the wispy hints of a narrative are further undermined by several moments of utter implausibility. So the farcical final scene feels particularly contrived. Even so, there are moments of real emotion and comedy. And there's something entertaining about spending time even with these deeply unlikeable people. Perhaps this is because watching people who are this silly and inept makes us feel like we have a chance.

Amid the political turmoil in 1973 Chile, flight attendant Lena (Watson) has a four-day layover, surprising her German journalist-activist boyfriend Daniel (Bruhl). But when the coup unfolds, they're detained by Pinochet's brutal soldiers. Daniel is taken away and cruelly tortured. Meanwhile, Lena inquires about his whereabouts, then sets off to rescue him from the Colonia Dignidad, an impenetrable religious compound where enemies of the state are hidden away and forced to work. Lena soon discovers that the charismatic Paul (Nyqvist) runs the community with an iron fist, assisted by his heartless housemaster Gisela (Carey).

The film has a realistic, urgent tone that's immediately gripping, building a quiet intensity even in the breezy opening romantic scenes between Lena and Daniel, which are interrupted by street protests and military action. As the action shifts to Colonia, the film begins to play with horror-movie imagery. When Lena arrives at the compound, she receives a series of "God bless" greetings, delivered like a Nazi salute. Daniel's experience is more overtly hellish. Yes, the entire community is nightmarish in its design and increasingly nasty details.

Performances also have an earthy intensity to them. Watson gives a superbly layered turn as a young woman the audience can easily identify with, bravely travelling into the danger zone. Her tenacity is deeply resonant, mainly because her chemistry with Bruhl is so compelling. And Nyqvist is terrific as the self-proclaimed saviour who might just be the devil incarnate. As is Carey as the smiley-but-monstrous supervisor. More sympathetic characters include Werner's hopeful fellow inmate and Krieps' helpful nurse, both of whom immediately seem doomed by their kindness.

Each shout of "what we do we do with love" is accompanied by further violence and abuse, much of which thankfully remains off-screen. But it's frustrating that filmmaker Gallenberger is more interested in echoing vile Hitler-era Germany than present-day religious oppression. And the intense final act has clearly been heightened for cinematic effect. But it's a thrilling story with engaging characters, and it highlights a horrific chapter from Chilean history that has rarely been reported.

Once relaxed and happy, Mark and Jonah (Karner and Milord) are struggling to cope with the fact that they seem to be drifting apart, and whatever they do to try and fix things doesn't seem to work. They visit a therapist (Ward) and make a few attempts to spark things up, but they simply can't reconnect. Back on anti-depressants, Mark begins flirting with fellow actor Kyle (Dits). And he is unprepared when his sister (Graf) arrives from Austria to talk about their father's recent death.

Told from Mark's perspective, actor-filmmaker Karner creates a tactile, thoughtful, loose tone that's more than a little evasive. The film repeatedly evokes echoing memories of a happy day the couple spent on the coast, but that moment feels so simplistic that there doesn't seem to be a real relationship to save. As a result, the film seems to mope aimlessly as Mark and Jonah talk about reigniting a romance that was apparently never there to begin with. As far as we can tell, they only ever vaguely liked each other. And Karner's depiction of physical intimacy is prudish and tentative.

Performances are strong enough to hold the interest, creating believable characters even if each person has the same too-focussed voice. There's all kinds of turmoil within Mark, but Karner oddly neglects to let the audience inside, so it's difficult to identify with him. Basically, Mark is deliberately disengaging, so there's no real sympathy for his moodiness. And the medical explanation feels like a narrative distraction.

This is an intriguing depiction of a relationship slowing down to a crawl, forcing each person to think about what has changed. The problem is that this means that the movie struggles to maintain any sense of movement. At least Karner is smart enough to know that there are no realistically easy answers. Yet while it's robustly shot and edited, and it touches on a number of pungently resonant themes, there's no point at which the audience can become involved in the emotional drama. So what should be a moving final scene only elicits a shrug.

Freddy (Silva) is a struggling artist hoping to land a commission at a local gallery for his video piece exploring the infant within him. This springs from his attempts to help impregnate his best friend Polly (Wiig), supported by his boyfriend Mo (Adebimpe). But when Polly fails to conceive, she asks Mo if he's willing to help. And this starts Freddy on a slide of self-doubt that affects his work. Meanwhile, they're being tormented by a crazy man (Cathey) in their street, and the clashes with him are threatening to erupt into violence.

While shooting and editing with a loosely comical energy, Silva packs the film with knowing character details that play cleverly with issues of gender, sexuality, race and mental illness. These are very big themes, but the filmmaker's light touch allows the characters to grapple with them in ways that are recognisable, from a tense birthday dinner with Mo's quietly homophobic family to interaction between neighbours who prefer to ignore each other. It's a knowing portrait of urban community interaction.

At the centre, Silva, Adebimpe and Wiig give raw, naturalistic performances as young people trying to be carefree about life while facing increasingly serious obstacles. The true nature of parenthood doesn't quite seem to dawn on them, which makes them startlingly easy to identify with, especially as the dynamics in their inter-connections become clearer. So the plot's insistent final act feels far too pushy, essentially turning the film into a thriller.

This shift in tone is so dramatic that it leaves the audience in the dust. Characters react in ways that seem oddly contrived, making them hard to sympathise with. The actors dive in fully to the demands of this intense, sometimes horrific final act, and where it goes is genuinely chilling. But it utterly abandons the relaxed, loose honesty of the film's first half. So the strikingly clever finale is essentially lost in the shuffle.