The apocalypse arrives as a series of collegiate sketches in the aptly-named Pity, the Rory Mullarkey play that may well prompt sympathy for audiences who unwittingly find themselves in attendance.

The NHS is us. For decades our national identity has been bandaged together with the idea, and reality, of a health service that is free at the point of delivery.

A raw pagan vitality animates this extraordinary story about a teenage boy wrestling with tumultuous emotions in the face of his mother’s terminal illness.

Les Dennis was once a marquee name on Saturday night television as host of Family Fortunes, but since giving up the light entertainment lark he now plies his trade as an actor, and a very good one at that. If you've not seen it, give yourself a treat and watch his bang-on-the-nose performance as “Les Dennis”, a delusional, whinging has-been, in Ricky Gervais and Stephen Merchant's Extras.

There's surprising and then there's The Lehman Trilogy, the National Theatre premiere in which a long-established director surprises his audience and, in the process, surpasses himself. The talent in question is Sam Mendes, who a quarter-century or more into his career has never delivered up the kind of sustained, smart, ceaselessly inventive minimalism on view here.

Britain is rightly proud of its record on multiculturalism, but whenever cross-cultural couples are shown on film, television or the stage they are always represented as a problem. Not just as a normal way of life, but as something that is going wrong. I suppose that this is a valuable corrective to patting ourselves on the back about how tolerant a society we are, but do such correctives make a good play?

It's been raining in Regent's Park. On a balmy summer evening during a prolonged dry spell – perfect for outdoor theatrics – it seems ironic to tempt fate by creating artificial downpours and thunderstorms.

"I am dead," declares Okot before recounting the horrors he survived to reach Calais. Each time, he says, "I died." How many times can you die before you are truly dead?

Aidan Turner may not reveal those famously bronzed pecs that have made TV's Poldark box office catnip in his West End debut. But what Michael Grandage's funny and fiery revival of The Lieutenant of Inishmore reveals in spades is the irresistible charisma and stage savvy of an actor fully at home in what can only be called Martin McDonagh-land.

History repeats itself. This much we know. In the 1980s, under a Tory government obsessed with cuts, the big new thing was “event theatre”, huge shows that amazed audiences because of their epic qualities and marathon slog. A good example is David Edgar’s The Life and Adventures of Nicholas Nickleby, an eight-and-a-half hour adaptation of the Dickens novel.