In a provincial town, restaurant owner Lian (Fan) launches legal action to declare her divorce from Qin (Li) invalid, because they only split to get a flat, and then he married someone else. But Justice Wang (Da) throws the case out. Her appeals escalate until she travels to Beijing to see her chef friend Zhao (Guo) and confront someone higher up. This causes chaos throughout the political layers for 10 years. Finally, the mayor (Zhang Jiayi) and county chief (Yu) team with Wang to find a solution, perhaps with the help of Zhao.

Scenes play out in a circle in the middle of the screen (or a square in Beijing), which creates strikingly gorgeous compositions, as if we're watching only part of the story through a keyhole. When combined with director Feng's knowing narration, watching the film feels like reading a very old storybook. On a big screen, it's easy enough to see the gorgeous detail in the costumes, sets and performances. On video this will be a challenge.

Performances are focussed and engaging, creating intriguingly enigmatic characters with all kinds of edges to them. Everyone clearly has a life off-screen, only showing part of themselves to others. At the centre, Fan is fascinating as Lian, a woman who is initially infuriating and then increasingly sympathetic as she refuses to be pushed around by these arrogant men. And they continually learn lessons from the intractable Lian, only to again prove their relentless self-interest.

While the story is satirical, it's sarcastic rather than funny. Still, there are amusing sequences, wonderful speeches and hilariously astute comedy. Lian's absurd quest never quite makes sense as an attempt to clear her name from accusations of infidelity (as the title suggests), although a startling final explanation adds emotional truth. Basically, this is a clever look at how impossible it is for politicians to avoid corruption, and for people to understand the tedious details of the law. It might even offer a cautionary warning about dictatorial governments and the weaknesses of democracy, but then the entire world is shouting that message rather loudly at the moment.

On France's north coast in 1910, Brufort and his son Ma Loute (Thierry and Brandon Lavieville) ferry visitors across the lagoon whenever the family isn't gathering mussels. The latest arrivals are Andre and Isabelle (Luchini and Tedeschi), who bring their extended family to their imposing summer villa, including Andre's histrionic sister Aude (Binoche). And Inspector Machin (Depres) also arrives from Calais with his sidekick Malfoy (Rigaux) to investigate a series of missing tourists, failing to notice that the Bruforts are eating them. Amid all of this, Ma Loute falls for Aude's gender-nonspecific child Billie (Raph).

There's a riotous contrast between the bickering locals and the giddy interlopers, with both the tourists and police adding plenty of slapstick wackiness. Everything is wildly heightened, from the Brutfort family diet and the buffoonery of the detectives to the ceaseless admiration the posh people have for the natural setting and the earthy working classes. Dumont packs the film with sight-gags, plays on words, edgy politics and unexpected emotion. And while the plot is freewheeling and seemingly unfocussed, it has its own internal logic.

Even if these people often seem like sketch-comedy figures, the fine cast gives them a startling underlying dignity. Each person has his or her own yearning, with motivations explained partly by their backgrounds. It's Ma Loute and Billie who bridge the gap, alternating between cracking the wealthy family's facade and puncturing the nobility of the natives. Lavieville and Raph also get to play the most complex, engaging roles as young people seeking acceptance outside their circles.

The nuttiness is rather relentless, but it definitely keeps the audience on its toes, especially as the script plays around with some seriously dark themes. And there are plenty of deranged moments to keep us chuckling. Dumont gleefully layers every moment with telling detail, often elements that undermine each other to reveal truthful attitudes and feelings. It looks spectacular, with witty costumes and beautifully raw settings. And a lighter-than-air element in the bonkers final act adds a touch of magic.

Shy 42-year-old Kostis (Papadimitriou) is the new doctor on the small Greek island of Antiparos. With a population of 800, everyone is on a first-name basis here, and they welcome him with advice about healthy living and hedonistic pleasures. When summer arrives, lively community parties give way to all-out depravity involving visiting tourists. His clinic also gets much busier. One patient is Anna (Tringou), a 21-year-old who sparks his interest. Soon he's partying with Anna and her pals (Hart, Kotsali, Van Groesen and Collen). But is he too old for all of this?

After a rainy, wintry prologue, the sunshine brings raucous energy to the film along with the crowds of visiting revellers. The movie also cleverly contrasts the responsibilities of Kostis' day job with his foray into a world of endless flirting and partying. Of course, he doesn't recover from a hangover as quickly as he used to do. But the real issue is that there's clearly something in his past that has left him a bit unstable when it comes to romantic entanglements, and as his feelings turn darker, so does the film.

The contrast between characters is sharply observed, both physically and in their attitudes and emotions. Papadimitriou is perfectly cast as Kostis, pudgy in his baggy trunks, hat and heavy suncream on a beach surrounded by young naked sunbathers. The actor nicely plays his ludicrous naivete. He's old before his time, and only vaguely aware of how ridiculous he looks surrounded by 20-year-olds. By contrast, Tringou's Anna and her pals are lively and free-spirited, unable to understand why Kostis takes everything so seriously.

As the story progresses, there's an oddly moralistic tone that emerges, repeatedly hinting that fun and sex should be left to lithe, tanned youngsters, while anyone older than 40 should settle down and start a family. That Kostis' partying starts to affect his job seems obvious. As does the fact that his feelings for Anna are deeper than hers for him. Still, it certainly isn't easy to watch as the film shifts from breezy coming-of-age into something that's deeply disturbing.

In Vienna, Stefan and Andreas (Turtur and Hochmair) have a happy life together with their tomcat Moses. Both work for a local orchestra, socialising with their colleagues, including clarinet player Lorenz (Stipsits), who's having a secret romance with another musician (Rubey). Then a moment of impulsive violence shifts Stefan and Andreas' relationship, pushing them to the breaking point. Deeply shaken, Andreas tries to get some help for Stefan, who is feeling overwhelmed by what has happened. The question is whether they can ever regain their equilibrium. Or do they need to start all over again?

Shooting in a documentary style, filmmaker Klaus captures this couple's warm, sexy home-life as well as their camaraderie with their musical colleagues. So when things take such a dark turn, it's genuinely shocking. The sense of loss is overwhelming, and where the story goes from here is unnerving since it never dodges the more difficult aspects of the subject matter. And as it depicts this couple trying to rebuild their relationship, the film takes some clever, telling turns. Some feel a little moralistic, but it's all thoughtfully provocative.

Performances are earthy and honest, with dialog that feels overheard rather than expository. This makes the cat into a main character in the story, especially since he's always up to something, hunting for critters in the garden or offering his opinion on what's happening in the home. In the opening act, Turtur and Hochmair have such easy physicality and lusty chemistry that where the story goes feels wrenchingly painful. Their interaction shifts and changes in complex directions that are skilfully expressed emotionally, mentally and physically.

Essentially, Klaus is exploring the fragility of trust, and how one momentary lapse can undermine even the most solid relationship. No, this isn't always easy to watch, and the film's unflinching, eerily intimate approach makes it increasingly challenging. Even more unsettling is the way it grapples with the idea of impulse control, one of the more horrifying aspects of being human, which we would much rather never think about. Thankfully, the movie finds hope in the power of a deeper connection.