Once Upon a Time in Nazi Occupied Tunisia at the Almeida Theatre – review

It's giving nothing away to say that in the opening scene of this new play, Victor, who is Jewish, is buried up to his neck in earth and Youssef, his best friend, who is an Arab, has been sent to urinate on his head by Tunisia's Nazi occupiers. Victor thinks, in fact, it might help; he's very thirsty.

Savour the complexity in that starting point for this funny, dark, and entirely original drama, which as an added bonus features a richly textured comic performance from Adrian Edmondson. Once Upon a Time in Nazi Occupied Tunisia confirms Josh Azouz as a playwright you want to keep watching. As he showed in the terrifyingly surreal Buggy Baby and in the gentle The Mikvah Project, you never quite know which way his bold imagination is going to lead him.

In this case, it is to 1943, just after the Nazis have invaded Tunisia, where their presence is putting new pressures on a society that has constantly had to adapt to colonialism and oppression yet appears to have forged its own tolerant character. Azouz and his designer Max Johns cope brilliantly with this period setting: the characters speak English throughout but tell us they are speaking different languages at different points; Johns has designed a set of white wood boxes that convey heat, allow burial and hiding, and at two points are opened to reveal the blue and white tiles of luxurious living. The characters wear clothes that are almost but not quite contemporary.

Combined with Jess Bernberg's lighting and David Gregory's unobtrusive sound, creates a setting that is once historic and universal, a place in which Azouz can explore themes that are at once huge – the rifts between the Jews and Muslims across many countries, the rise of Zionism – and specific, in the shape of the domestic drama that binds together Victor and Youssef and their wives, Loys and Faiza.

Into this mix, the Nazis arrive like a grenade, but even they have strangely domestic names such as Grandma, Little Fella, and Memento, comic book characters who are all the more terrifying because they seem so ineffectual. "You should be afraid," Edmondson's urbane Grandma (so-called because he likes knitting) hisses at the imprisoned Victor. "Any Nazi with prospects is in Europe. They only send animals to Africa."

Edmondson is without doubt the star of the evening. Even hobbling on a stick, necessitated by a knee injury, he brings a blast of unnerving energy to proceedings. Like the snakes with which he is obsessed in one monologue, he has a coiled malice that hides beneath the civilised surface he presents to the world; when the madness breaks forth it is both mesmeric and frightening.

He's such a physical actor, with a kind of clumsy grace in every gesture. A long, dinner scene, between him and Yasmin Paige's vital, vivid Loys, is underpinned by real tension as Nazi confronts liberated, rich Jewish woman, and they debate questions of identity, anti-Semitism, and human rights with animation and passion. Yet a shocking chill enters the conversation about whether a person is defined by one aspect of themselves or many, when suddenly Edmondson leers: "What a thrill to be so close to Jewish hate."

Other scenes lack this degree of clarity. There are many brilliant moments, but the overall effect of the piece is muted by its digressive form – there is a lot of history and a lot of drama to cram in – and speeches of exposition that break into the arc of the drama. The pacing of Eleanor Rhode's direction and some performances seem uncertain too, though Pierro Niel-Mee's Victor makes the most of the character's infuriating qualities, and Ethan Kai's Youssef allows his essential sweetness to glimmer through his posturing.

One of the many qualities of Azouz's writing is his ability to create characters who are flawed, who do represent many things rather than a single aspect of themselves on stage. Even when the execution doesn't quite match his ambition, his writing and his ideas have a freshness, a challenge and a humanity that makes them worth spending time with.