The Duchess of Malfi, NT Lyttelton, London<br></br>Midnight's Children, Barbican, London<br></br>Victory at the Dirt Palace, Riverside Studios, London

Dirty deeds in dismal times

First things first. I'd like to beg Eleanor Bron's pardon for my lack of restraint. When the National staged The Duchess of Malfi back in the 1980s, a school friend and I got such appalling giggles about the production's portentous ticking clocks and proliferating corpses that we set the whole front row off. At the curtain call, Bron and her courtiers rose from the dead, turned as one, and looked daggers at us.

This time round, John Webster's revenge tragedy proves heartrending as well as ferociously chilling. That's thanks to superb acting, especially from Janet McTeer as the titular heroine who is cruelly punished for secretly marrying her steward Antonio against the orders of her repressive brothers – the incestuously obsessed Duke Ferdinand and a shamelessly criminal cardinal.

In Phyllida Lloyd's modern dress production, which hovers between the 1930s and today, Italy is a dark chasm that looks simultaneously grand and creepily austere (as designed by Mark Thompson). Ferdinand's entourage amass on a wide flight of steps and watch the harrowing tale being played out, like spectres caught in pale shafts of light. This is also a political thriller with some contemporary satire thrown in. Will Keen's short, balding and sharp-suited Ferdinand makes his first dictatorial pronouncements into a microphone, grinning for the media circus like a game show host. Behind the scenes, he coldly bribes the hit man Bosola – with used cash in an attaché case – to spy on and torture his sister.

There are some peculiar weak points in this piece. You'd have to be a dummy not to discern, in Act Four, that the supposedly hanged bodies of Antonio and the Duchess' infant son are fakes. Lloyd's use of film becomes badly strained, too, when she replaces Webster's scene of gibbering madmen with a hallucinatory "pop video" nightmare which McTeer has to endure, strapped into a chair. One might accuse Lloyd of nabbing directorial concepts as well – see Declan Donnellan and Michael Boyd for game show-style politicians and ghosts wandering around like guilty consciences. Also, Webster's most risibly melodramatic props and plot twists – not least a poisonous Bible – remain glaringly obtrusive and raised some disbelieving titters on press night.

However, Webster's poetry glitters brilliantly, as in the Duchess's fearless embracing of her brutal murderer: "What would it pleasure me to have my throat cut/ With diamonds or to be smothered/ With cassia or to be shot to death with pearls?" Webster's turning of the emotional screws often proves electrifying too, combined with this cast's vibrant naturalism.

McTeer's Duchess is a beautifully rich mixture of towering dignity, courage, suppressed fear and innocently teasing sensuality. Her relaxed intimacy with Charles Edwards' Antonio – curled up on their bed, almost unthinkingly caressing his shoulder – makes their sudden enforced parting the more unbearable. Lorcan Cranitch's merciless Bosola makes your hairs stand on end, precisely because he looks like a banal, stolid businessman. Meanwhile, Keen's incurably screwed-up Ferdinand manages to be amazingly sympathetic, crumpling beside the lifeless McTeer, touching her hips and weeping, his speech disintegrating into a stuttering hum of grief.

The narrator, Saleem, in Salman Rushdie's Midnight's Children is also incestuously hung up about his sister, and that may be a larger political metaphor. For Saleem – a stiffly waddling Zubin Varla – was born as the clock struck 12 in mid-August 1947. That's the instant when India was liberated from British rule but also became (or remained) embroiled in internal troubles – between the religious and the liberal, between Hindus and Muslims, over Pakistan, corruption scandals and so on. In this tale of four generations, the body of Saleem's grandmother is "partitioned", inspected in sections through a punctured sheet by her European-educated husband-to-be. And Saleem's own flesh has, apparently, been fissured by sustained conflicts, though he craves peace and harmony.

Unfortunately, you may hardly log these points – let alone emotionally or intellectually engage with them – during the three-and-a-half-hour dire mess the RSC has made of Rushdie's novel (drawing in part on a ditched screen adaptation). If the book is narratively meandering, slipping between past and present, at least it offers vivid descriptive details of lush landscapes and bustling cities, eccentric characters and bloody conflicts.

The stage version, for which Rushdie, dramaturg Simon Reade and director Tim Supple are responsible, is both interminable and ludicrously rushed. It's an incomprehensible whirlwind of vignettes, mostly peopled by tiresome comic caricatures. Though designer Melly Still drapes bright silk around the stage, Supple seems thin on imagination. Snippets from old newsreels aren't decently integrated and the new video footage is drab, picturing a crowd who are meant to represent the voices Saleem hears in his head.

Obviously Rushdie's concerns about religious rage and tense East-West relations are topical and this a brave project in many respects. But theatrically, it's excruciating. One feels all aesthetic hope draining away long before Saleem gets round to talking about his compatriots undergoing a political "sperectomy" (the excision of all optimism).

Far more exhilarating and bold is the Riot Group's radical reworking of King Lear, which I caught on tour at the Riverside Studios and which deservedly won a Fringe First at Edinburgh last year. Victory at the Dirt Palace, written by Adriano Shaplin, transmutes Shakespeare's old English monarch into a power-crazed but ageing US newsreader called James Mann. His TV empire is embroiled in a desperate ratings battle with a rival channel where his bitter – possibly abused – daughter rules the roost but faces a scathing exposé of kinky romps with her producer.

Though the dialogue is too relentlessly rapid-fire and the characters' ravings can be obtuse, this is a ferocious and slick farce. Everyone stares icily out front as if eternally ready for the cameras to roll. Chilly professional posturing is intercut with wildly vicious personal phone calls, and modern slanging matches are unsettlingly shot through with archaic curses and a subtle lyricism. A young troupe to watch.

k.bassett@independent.co.uk

'The Duchess of Malfi': NT Lyttelton, London SE1 (020 7452 3000), to 10 March; 'Midnight's Children': Barbican, London EC2 (020 7638 8891), to 23 Feb, then touring (RSC hotline: 0870 609 1110); 'Victory at the Dirt Palace': Drama Centre, Cambridge (01223 511511), 20-21 Feb; Nuffield, Southampton (023 8067 1771), 25-26 Feb; Contact, Manchester (0161 274 0600), 27 Feb to 1 March