There is more than a whiff of martyrdom about this week's big West End show. In Jean Anouilh's Becket, Dougray Scott plays the brooding, eponymous Archbishop of Canterbury who is slaughtered in the cathedral for resisting the demands of his erstwhile friend, Henry II. Then Jasper Britton's King Henry is seen stripped naked, in penance, waiting to be flagellated.
To be upbeat for a moment, John Caird's revival of this costume drama shows how the anxieties which the French playwright felt in the 1950s - concerning racial hatred and cycles of genocide - remain pertinent.
Here envisaged as a Saxon with Arab blood in his veins, Becket works with his Norman rulers but finds institutionalised bigotry in the royal family, Church and armed forces. In Frederic and Stephen Raphael's pointed new translation, Britton's Henry also finishes with a declaration that one of his blood-stained barons will head an "independent inquiry" into Becket's death.
Stephen Brimson Lewis's black-arched set is plain and simple, but the show's strength lies in its central performances. Britton is an extremely deft actor with a deceptively rumpled aura. He conveys, without overplaying, the King's jovial laddishness, arrogant brutality and insecure neediness. Scott's contrasting portrait of Becket is assured and well-sustained in its ambiguity: exuding humane gentleness and an elusive cool which might conceal ambitions or festering vengeance.
That said, this play grows heavy-handed, as the action veers towards the didactic and resorts to crass comic relief. Anouilh induces increasing ennui and Caird's production is not always finely judged, with several poor cameos and slow pacing. The fey King of France (Michael Fitzgerald) is an excruciating caricatured bore, milking every line. Becket's murder is also feeble, with a clumsy segue into the whipping with much slow-mo sword-waving. Sometimes you wonder who is suffering most: Britton, Scott or the audience.
Acts of treachery also threaten everyone in The Mandate. The most remarkable thing about this lesser-known Russian play by Nikolai Erdman - championed by Meyerhold in 1925 and now admirably revived by Declan Donnellan - is its conjunction of humour and terror. The scenario is frightening. Under Stalin's new regime, the Guliachkins are frantically trying to refashion themselves, but they remain bourgeois and closet Christians and are entangled in a plot to reinstate the Romanovs. Madame Guliachkina's son, Pavel, lives in fear of the authorities knocking at the door, and their lodger, Ivan, threatens to turn informer.
Yet this is not a suspenseful thriller. Erdman's chosen genre is farce. Ivan is livid because the Guliachkins have banged on his wall and a cooking pot has fallen on his head. Adrian Scarborough, thus crowned, scuttles around looking daggers between a fringe of noodles and a huge droopy moustache. He is also aquiver because he's got the hots for the cook, Anastasia. In this role, Naomi Frederick rabbits away in a pricelessly funny, pea-brained singsong. Meanwhile, Deborah Findlay's Madame Guliachkina and her offspring are business folk ludicrously affecting to be intellectuals and getting into a pickle, still trying to marry into the aristocracy.
Erdman's plot twists are occasionally silly and strained. Also, with the comedy predominant, the last-minute plunge into a grim psychological and political chasm feels bemusingly sudden. Pavel asks, "If they won't even arrest us, Mummy, how can we live?", the walls are rent asunder and gunfire strafes the air. However, that question and designer Nick Ormerod's coup de théâtre have reverberations going way beyond 1925.
The precise date of The Mandate makes it fascinating too. Not only is it about people in cultural transition, it's also remarkable to think this political satire got staged, briefly uncensored, before Stalin cracked down and Erdman was dispatched to Siberia. Politics aside, Donnellan's lively translation is a joy and so are his whole cast, who even turn the scene changes into farcical chases with flying furniture. It's splendid to see him and Ormerod (aka Cheek By Jowl) back at the National.
David Farr is to take over at Lyric Hammersmith next year, having impressively energised Bristol Old Vic over the last couple of years. However, his new production of Twelfth Night isn't his best work. Set designer Angela Davies' vision of Illyria is beautifully imaginative, alert to the strains of loss, mourning and decay that intertwine with the play's hopes of rebirth. The realm where Nikki Amuka Bird's shipwrecked Viola washes ashore - bursting through the floor, dripping with water - is a lovely but half-ruined mansion. A huge hole gapes in the wall above the neo-Classical tracery and the stopped clock. Charles Edwards' Count Orsino sits weeping in front of a flickering telly, in specs and a tank-top, like a 1950s/contemporary aristocrat emotionally collapsing along with his ancestral pile.
The main trouble is the cast is uneven in quality and most of the comedy falls flat, with the exception of Mark Lockyer who is having a ball as Malvolio, strutting around like a dog on its hind legs. Amuka Bird is effortlessly boyish, with her hair slicked back, yet the sexual confusions this creates are not fully explored. Jimmy Yuill's Sir Toby, like a debauched Chekhovian gent in his grubby linen suit, has potent flashes of rage, but Ian Lindsay's Feste just looks clueless as he drones the final song, "Hey ho, the wind and the rain". Something of a damp squib.
Finally, Tropicana was supposed to be a hot ticket: a promenade show devised by the acclaimed performance collective Shunt, backed by the NT, and leading you round a gigantic labyrinth under London Bridge Station. The journey starts magically, as you are ushered into what appears to be a cleaner's cubby-hole; a locker swings open and, Narnia-like, you squeeze through the coats to The Other Side.
Unfortunately, once you are down in the dark maze of brick arches, the evening goes nowhere, theatrically speaking. Shunt have hopelessly, lazily lost their way here and Tropicana is a lamentable waste of space. There are a few memorable images: an impish face popping through a door panel; an old elevator, complete with uniformed attendant, sliding sideways through the night; a hand plunging into the gut of a phenomenally convincing corpse. But really it adds up to little more than a pretentious son et lumière with a handful of surreal speeches tossed in for a laugh. One can only blush for a collective who thinks it's cutting-edge to have bikini-clad dancing girls splaying their legs on the bonnet of a hearse and selling beer out of a coffin.
'Becket': Haymarket Theatre Royal, London SW1 (0870 901 3356), to 12 Feb; 'The Mandate': NT Cottesloe, London SE1 (020 7452 3000), booking to 15 Jan; 'Twelfth Night': Old Vic, Bristol (0117 987 7877), to 20 Nov; 'Tropicana': Shunt Vaults, London SE1 (020 7452 3333), to 16 JanReuse content