Roman Polanski may not be known for comedy; his last, Pirates, was 25 years ago and hardly a bundle of laughs.

But Carnage is a scream, an outrageous comedy of manners that exposes prejudice, hypocrisy and lies among the middle classes, and is wonderfully unhindered by decorum.

Adapted from Yasmina Reza's play The God Of Carnage, this remains a four-hander, but with the setting switched from Paris to New York. After a fight between two boys in a local park, the parents of the victim, Penelope and Michael Longstreet (Jodie Foster, John C Reilly) invite those of the bully, Nancy and Alan Cowan (Kate Winslet, Christoph Waltz) to their home, in a bid to deal with the problem amicably. The meeting goes well, and the Cowans prepare to leave, their task of token apology achieved. But Penelope wants more; she wants to hear it from the boy. With the elevator in sight, the Cowans return to the apartment.

It's a bad idea. The more the couples talk, the more apparent is their distaste for each other; more than that, there's little love within the couples themselves. As coffee and cake turns to scotch and cigars, inhibitions fall away and the apartment becomes a verbal war zone. The actors are pitch perfect: Foster shrill and hectoring and a terrible advert for political correctness; Reilly a believable blue-collar guy whose success has not smoothed the rough edges; Winslet proving a great comedienne, as the character with the most spectacular volte-face in store; Waltz typically mischievous as Alan, the most openly diabolical, a lawyer who can't stay off his cell phone and takes great pleasure in baiting Michael over his "flushing mechanisms".

They are marshalled brilliantly by Polanski. Can it be coincidence that the first film the director has made since being freed from house arrest in Switzerland (battling extradition to the US over the sex charges that have haunted him since the 1970s) should be restricted to a single interior set in which the characters totally lose their senses? I think not, and I have to admire the Pole for his novel way of using (perhaps exorcising) his recent experience.

He's a master of making the most out of interiors, in any case, and his control of the space and a number of key props – notably a mobile phone, a fruit cobbler, a bucket and a hairdryer – is a joy to behold.

The drama Martha Marcy May Marlene deals with a peculiarly American phenomena – the cult – raising pertinent questions about the difficulties faced by anyone attempting to leave such an unusual situation and return to normal life. When Martha (Elizabeth Olson) escapes a rural, cult-like community in the Catskill Mountains, she turns for refuge to her estranged sister, Lucy (Sarah Paulson), moving into the lakeside home shared by Lucy and her husband Ted (Hugh Dancy).

Rather than relief, Martha feels only confusion, repulsed by a materialist lifestyle that reminds her why she was attracted to the self-sufficient, farming existence of the cult in the first place, but at the same time haunted by memories of the abusive rule of the cult leader (John Hawkes). She's all over the place, torn between these two inadequate "families", and wracked by a paranoia which is rooted in the real threat still posed by the cult.

Writer/director Sean Durkin creates a persuasive sense of unease, in which he is greatly aided by Olson's distracted, otherworldly presence. Hawkes follows his memorable, coke-addicted anti-hero Teardrop in Winter's Bone with a performance that is finely balanced between charisma and creepiness.