As a play and as a performance there are elements of Splendour that I have not seen bettered this year. At the curtain call, I found myself with a reflex-like conviction in its quality. My reaction was enjoyment at a base physical level that I could not explain. Abi Morgan’s script and its delivery are captivating throughout. This is because both elements are undeniably adventurous without ever becoming forced. But the mechanics require and demand a masterful hand. Splendour threatens to slip through the fingers of the unworthy, and shatter on the linoleum.

The action of shattering is key to the piece, and is reflected in Peter McKintosh’s striking set design. He borders the stage with a coat of smashed glass so heavy it could be giant salt crystals. The plot centres around four women and an evening of drinks. Travel photographer Kathryn (Genevieve O’Reilly) is being hosted by Micheleine (Sinead Cusack), the wife of an infamous foreign dictator who should be returning home any minute. Joining them are Genevieve (Michelle Fairley), Micheleine’s closest friend, and Gilma (Zawe Ashton), Kathryn’s interpreter. We are in the public rooms of the capital’s plush presidential mansion. Outside, civil war threatens to spill over from the country’s rebellious northern states into the capital’s streets close by.

To begin, the characters introduce themselves with reasonable success through Gilma, who is far more interested in thieving Micheleine’s nick-nacks. But the action is sporadically halted by the blinding flash of a camera, whiting-out the stage and restoring us to an earlier moment. Events repeat themselves but – like an accidentally shattered and hastily repaired glass – do not fit together as snuggly as they did in the previous run through. Lines are truncated, altered in tone, or transposed for a different character. Each new journey – often delivered with lightning alacrity – slowly unwraps the characters’ layers of concealment, and makes for astoundingly impressive work.

The idiosyncratic form requires each of the actors to display some serious emotional gymnastics, which are performed admirably. Fairley feels most adept in this area. When the play chooses to focus on her for a moment or a scene it is often easy to mistake her for the sole protagonist. Cusack makes a charismatic first lady, who has us in her palm. When she addresses the audience at regular intervals, she really works the room. She’s looking someone directly in the eye, but has the uncanny ability to make even those looking at the back of her head feel like it’s them. Ashton has a penchant for deadpan that is well utilised, especially when she happens (or chooses) to leave some of her work lost in translation.

It was only in Kathryn that I was left wanting. While O’Reilly often catalysed my engagement in an anecdote or piece of dialogue through her own enthusiasm, I felt that her character plays the part of the lens through which we watch the action too much. As someone experienced in foreign atrocity, it was strange to see news of the shocking reality outside the palace’s gilt windows leaving her unmoved.

Ultimately however, director Robert Hastie has crafted an exemplary ensemble piece, whose compositional elements are equally in tune with each other. What begins in chaos transitions fluently into a complex and fulfilling narrative. Each of the women’s histories, their relationships with each other and with the country are well developed as the evening progresses and proves vital to their eventual fates.

There are too many plays in the West End that aren’t willing to risk enough to give their audiences something truly enthralling, and more than enough examples, particularly in the fringe, that shoot for the moon but know they can’t do justice to an ambitious central ideal or idea each night. Splendour should shame the former and give hope to the latter. These women make it look easy to turn a challenging script into material that is unilaterally precise, and of a quality that should serve as a model to all those lucky enough to see it.

Splendour plays at the Donmar Warehouse until 26 September. For more information and tickets see the Donmar Warehouse website. Photo by Johan Persson.