The Arsonists, Royal Court Downstairs, London<br/>The Car Cemetery, Gate, London<br/>The Giant, Hampstead, London

Max Frisch's sinister Fifties farce threatens to drop a bomb on comfortable bourgeois assumptions

Mr Biedermann's loft has been packed with oil drums that smell, ominously, of petrol. This well-to-do homeowner's attic has been taken over by a supposedly destitute duo who got their foot in the door. Now one of them, the ex-jailbird Eisenring, is coolly unrolling a fuse and he says his pal, Schmitz, has nipped out to steal some firelighters. So why does Mr Biedermann seem blind to the incendiary situation?

In a fine new English translation by Alistair Beaton, Max Frisch's weirdly gripping play The Arsonists (aka The Fire Raisers) manages to be satirical, menacing and mysterious. Will Keen's uptight Mr B is like a bourgeois fool in a farce, only the set-up here is sinister and politically loaded. In a brilliant, precision-tooled performance, Keen doesn't notice the kegs under his nose. Then, doing an aghast double-take, he becomes a human hairpin bend, his head shooting down to knee-level, eyes bulging at the big red signs reading "FLAMMABLE". He treads a terrific fine line between serious tension and comic flair.

Ramin Gray's production – in which the bomb sits directly over the Biedermanns' chic white dining-room – keeps you reassessing what Frisch's scenario symbolises. Who are these modern Guy Fawkeses? Might they be related to the current "war on terror"? The pseudo-Sophoclean chorus of firefighters hovers constantly on the sidelines in 9/11-style gear, like a paranoid but hopeless surveillance operation.

Biedermann can be viewed as the embodiment of placatory cowardice, either individual or national. He adopts an accommodating chumminess in the mistaken belief that the criminal underdogs will then leave his property intact. At the same time, The Arsonists feels like an allegorical psychodrama. It's as if the spirit of anarchy has sneaked inside Biedermann's head as well. Whilst he is in denial about what's going on in the attic, a part of him is complicit with the imminent decimation of his world.

Some artistic decisions taken in this staging are debatable. Translating the action to the present day obscures the fact that this is, in fact, a 1950s play about (among other things) the rise of the Nazis. Several of the social types, updated, don't seem consistent. Yet that in itself proves all the more thought-provoking, and almost everything is persuasive in the end.

Strong supporting performances are supplied by Benedict Cumberbatch as an icy Eisenring, and Paul Chahidi who, as Schmitz, combines an affable manner with creepily cold eyes. There are wonderfully quirky moments too, not least when the firefighters officiously stamp out a cigarette butt and, from there, slowly break into a tap routine. Recommended.

The Arsonists was not the only wacky European drama from the Fifties to be revived this week. The Gate's new co-artistic director, Natalie Abrahami, has chosen to stage Fernando Arrabal's The Car Cemetery. The Spanish-born, Paris-based playwright has been awarded the Légion d'honneur and an Académie Française Grand Prix and is said to be, worldwide, the most performed living playwright. But not in Britain, he isn't, and now we know why. The Car Cemetery is a crashing bore.

OK, Abrahami's young designer Lorna Ritchie has strikingly transformed the whole auditorium into a junkyard – all black tarpaulins and battered vehicles. The trouble is the unfolding drama. It's like a garbled, sub-standard variation on Beckett's Endgame (published the same year) with deeply tedious bouts of sadomasochism attached and crudely obvious Christian imagery. Think post-apocalyptic Gothic. The wrecked motors are serving as some nightmarishly sleazy hotel. Bestial grunts are heard from inside sepulchral car boots. A leering, Igor-like figure beetles around in a frayed tail-coat. There's a glimmer of hope when the young abused tart, Dolya Gavanski's Dila, gets together with David Ricardo-Pearce's Emanou who is meant to be a cult rock musician/messiah-type. However, he's not got a firm grip on his belief in goodness and is crucified by whip-wielding, leather-clad police officers.

Perhaps another production could have been more shockingly raw, but this is just deadly. The acting is uneven, the S&M unconvincing and, at other points, nothing of any interest is happening on stage. To put it politely, this is a pile of scrap.

Meanwhile, two great Italian artists are depicted competing in Anthony Sher's new historic drama, The Giant. John Light's Michelangelo, though insanely moody and not yet famous, wins the commission to sculpt Florence's prize block of marble into his towering nude statue of David. Roger Allam's mellower Leonardo doesn't seem heartbroken, being multitalented and more interested in learning how to fly. But both men – while struggling to suppress their homosexuality – are enamoured of Vito, the young lad from the quarry who's become Michelangelo's model.

This is better than Nigel Planer's laboured Sistine Chapel comedy, On the Ceiling. There are touching moments of tenderness and I learned a few things about Florentine history, including its period of extreme repression under the zealous friar Savonarola. Sher writes clearly delineated characters and gets the stage nudity off to an amusing start with a impish aged man (Richard Moore) merrily dropping his pants, giving us a full frontal and then introducing himself as the Old Vito. Directed by Greg Doran, newcomer Stephen Hagan is, in turn, beautifully natural as Vito's youthful incarnation. However, other scenes teeter on melodrama, with Light's guilt-wracked Michelangelo pursued by jibbering monks. Moreover, while we hear how Michelangelo breathed life into stone, Sher writes floridly metaphorical dialogue that rings false. You almost hear the big themes – art, beauty, politics et al – landing on stage with a clunk.

need to know

Max Frisch is one of the most significant figures of 20th-century German Literature. Born in Zurich in 1911, he came into his own as a prolific diarist, journalist and playwright just as the rest of Europe was imploding under the Nazis. From the safety of neutral Switzerland, he was at liberty to tackle questions of identity, individual guilt and social responsibility in work that would certainly have been censored elsewhere. Together with Friedrich Dürrenmatt, the Swiss author of 'The Visit', he was able to nurture a German-speaking theatre tradition that could comment on the atrocities, well out of the reach of National Socialism.

Further reading 'Frisch: Three Plays' (Methuen) includes 'The Fire Raisers'

'The Arsonists' (020 7565 5000) to 15 Dec; 'The Car Cemetery' (020 7229 0706) to 1 Dec; 'The Giant' (020 7722 9301) to 1 Dec.