David Lewis's fourth play to be premiered at the Orange Tree is another wonderful example of this theatre in the round's speciality of doorless farces. Like Stoppard and Frayn have done so successfully in the past, though, Monkey's Uncle is both a farce and an exploration of the nature of farce. Fortunately, Lewis' self-conscious, postmodern take on the genre avoids the danger of becoming merely a tediously self-referential exercise and manages to be at once genuinely funny and thought-provoking.

The first two acts take place in belle époque Paris, where we see farce writer Georges Feydeau (an engagingly bemused David Leonard) caught up in an increasingly complicated web of sexual shenanigans from which he struggles to extricate himself. Awakening from a disturbed sleep after a night of debauchery, he tries unsuccessfully to placate his much-put-upon wife Marianne (sympathetically played by Amanda Royle) while concealing his mistress, the cabaret performer Cecile (a suitably seductive Beth Cordingly), who is pursued both by another lover, doctor Didier (Stuart Fox, who is extremely funny and increasingly desperate), and by her husband, police inspector Habillot (Alister Cameron, who makes the most of Habillot's 'novelty act' of animal impressions.) The action then moves to a hotel room where, due to a series of misunderstandings, everyone bumps into each other again.

So far the format is one of traditional farce, but Act Three fast forwards to early 20th-century London, with the actors playing modern-day counterparts to the characters they played before. Here, George, a well-known sitcom writer, is trying to finish off a farce he has written about, yes, you guessed, Feydeau, while attempting to save his marriage.

Lewis' achievement is to provide a highly entertaining madcap plot, while commenting on the human motives that drive the mechanism forward. We have all the classic ingredients of farce, such as people hiding under the bed, trousers dropping down and billets doux going astray. But underneath is an examination of how basic animal instincts can easily override bourgeois morality and social convention. With references to Darwin and Freud, Lewis suggests that civilised behaviour is an ideal that denies the reality of primitive feelings.

It's a tribute to Sam Walters' superb direction that, while the pace does not flag, the comic business never becomes wearisome. As there are no doors for the characters’ continuous exits and entrances as they go about looking for or escaping from each other, the actors mime opening and closing doors, with the sound effects supplied in view of the audience, just off-stage – a very appropriate device of course for such a metatheatrical play.

- Neil Dowden