The mystery of mathematics for most of us means memories of algebra lessons at school, or the dismay with which we learned that, having scraped through O-Level maths by two marks, there loomed another O-Level hurdle of additional maths (I fluked that, too, by one mark).

But the mystery of maths at the highest level turns out to be a thing of real beauty in A Disappearing Number, Simon McBurney’s intriguing, very beautiful new show for Complicite, co-produced with the Barbican, Theatre Royal Plymouth, and festivals in Vienna and Amsterdam.

The hinge is the remarkable friendship, around the First World War, between the Cambridge mathematician GH Hardy, who believed that mathematicians were only makers of patterns, like poets and painters, and the Brahmin vegetarian autodidact Srinivasa Ramanujan. The air of magical contrivance is sustained by encasing this friendship in the expositions of a narrator physicist and a Hardy disciple many years later.

The extraordinary formula of a series of numbers adding up to a mere twelfth (the subject of Ramanujan’s first letter to Hardy) remains mind-bendingly baffling, but an audience is pleasantly seduced, and never patronised, by the problems of zero, the partitioning of integers and other such phenomena, while the story develops.

The physicist (Paul Bhattacharjee) even plays the old numbers game of showing how we are all thinking of the same one at the same time. The disciple Ruth (Saskia Reeves) boldly declares that one plus one equals three: she’s pregnant! Prime numbers are the bones of maths; the flesh is the infinite system of equations and theorems that not so much defy logic as make logic seem inadequate to understanding.

Ruth is in bed with both her subject and an Asian businessman in the futures markets who, in turn, is trying to have a telephone number changed in long-haul conversations with a BT operative in Bangalore. That number echoes a taxi cab number in another part of the narrative – 1729 – which Ramanujan (the delightful Firdous Bamji) casually identifies as the result of two cubes multiplied in two different ways.

Nothing is accidental in numbers, as it is in life. In a richly various musical soundtrack, composer Nitin Sawhney has written a wonderful maths rap, danced with rigid muscularity, and the lighting and projections of Paul Anderson and Sven Ortel takes us fleetly from lecture halls to the teeming streets of Madras and the quiet majesty of Trinity College where Hardy (David Annen) pores over his papers. Now, if you’ll excuse me, I must return to my fractions.

- Michael Coveney