Sam Walters, Britain's longest-serving artistic director of a theatre (43 years!), looks to the past as well as the future with his Orange Tree swansong. This varied festival features nine plays and six world premieres across two programmes, all of them staged by returning graduates of the Richmond venue's trainee director scheme. The diligent Programme One viewer will spot a number of recurring subjects, including science teachers and astrophysicists, the resurfacing in adulthood of childhood dynamics, and constant grappling with faith and mortality.

In French, when you want to end a digression and get a conversation back on point, you say "revenons à nos moutons". It's a commonly used idiom, meaning literally "let's get back to our sheep", the sheep representing the  actual subject under discussion. It also offers a way of looking at David Mamet's one-act play Squirrels, too, for no matter how far away their flights of imagination take them, the characters will always find their way back to their original theme, with a little help from an improbable animal – a squirrel, not a sheep, but you get the idea.

Usually, to describe a play as "of its time" is a criticism. It is suggestive of drama that hasn't aged well, that doesn't work quite as well for today's audience as it did for the original crowd. First performed in 1847, Dion Boucicault's The School for Scheming seems at first glance to fall into this category, with its mannered language, twisting plot and moral overtones.

It's unusual for a play to be political without being preachy, or dull, or both. As obsessed as we are with class distinctions, we aren't as good as we should be at pulling them apart. Invincible is therefore something rare, for it turns social distinctions into compelling comic drama.

Alan Ayckbourn is generally considered to be the master of this kind of writing. Given that, it is perhaps unsurprising that Invincible's writer, Torben Betts, has worked as a resident dramatist at Ayckbourn's famous stomping ground, the Stephen Joseph Theatre in Scarborough.

Would you be able to tell if the world had ended? For Beth and Franklin, the wannabe intellectuals at the heart of Stephen Sewell's play, it proves quite difficult to ascertain whether life as they know it has come to an end from their privileged life high in a luxury Melbourne apartment. Whether they are bickering about how the New Yorker has gone downhill or despairing about terrorism, they remain insulated from the world by their own self-absorption.

Adapt a Jane Austen novel for the stage and you have a generous handful of characters and a selection of drawing rooms in which to put them. Adapt a George Eliot novel and you’re faced with a whole town of people – figures from grand houses, workhouses and everything in between. It’s quite a task, but one that Geoffrey Beevers has made his speciality. He’s already tackled Silas Marner and Adam Bede but now, in a new triptych of plays for Richmond’s Orange Tree Theatre, he takes on the big one: Middlemarch.

The American repertoire has featured big-time on the London stage this year but perhaps nowhere more oddly than courtesy the ever-adventurous Orange Tree's staging of a World War Two play from Susan Glaspell, here receiving its world premiere.

Although overwhelmingly remembered now as a novelist, Somerset Maugham was best known during his lifetime as a playwright. “England’s Dramatist”, as the newspapers christened him, produced more than 20 plays spanning the length of his career, outdoing contemporaries Shaw and Rattigan for popular and critical success. But his was not an enduring fame, and with his work now strikingly absent from the theatrical repertoire, any revival must inevitably face the suspicious question: why?

When's the last time you encountered a play with a hissable anti-hero and a young heroine who radiates charity, decency, and all things good? Those polarities are on full-throttle view in The Stepmother, the all-but-unknown Githa Sowerby play from 1924 that makes up in its vigorous appeal to the jugular what it may lack in dimension and subtlety (Chekhov this ain't.) And if the opening night is any gauge, Sowerby's tale of a young wife and her unctuous, much older rapscallion of a husband has a demonstrable capacity for evoking responses from the crowd.