I studied maths at university, so I understand the concept of twin primes: pairs of numbers which are close together, but as mathematically unrelated as it's possible to be.  This interesting experimental show presents eleven short scenes over the course of 50 minutes, each featuring two people who are brought together by circumstances, yet are distant from each other too.  Some segments are highly effective, but others misfire, and the show as a whole lacks a little coherence.

The opening moments are perhaps the weakest, especially because the unusual structure of the play takes a while to settle into.  With rapid costume changes and series of striking characters, it feels at first like a sketch show which is missing its punchlines.  There is humour in these early scenes – such as the deliciously-observed business guru with his love of the word "literally" – but in the end they all seem to fizzle: neither properly funny nor particularly thought-provoking, they often left me wondering whether these particular stories were really worth telling.

But the show hits its stride about halfway through.  A subtly disturbing story about a meeting in a luxurious hotel develops into something appallingly dark, but in its way, quite lyrical.  And later vignettes are powerful too: there's a monologue at a hospital bedside, which is brutal and distressingly easy to relate to, and a sensitive scene set at a football match which explores the nature of male relationships in occasionally-surprising ways.  A best-man speech gone wrong provides the distilled essence of awkwardness, and the final scene tackles a topical issue in a way that's simple and straightforward enough to bring it truly home.

The problem is that, when each vignette is so short, it doesn't have time to develop either characters or theme.  Playwright Florence Read is surely aware of that, so I was searching for some kind of over-arching narrative: a thought which would be picked up from scene to scene, built and reinforced as time goes on.  But although there are occasional echoes between the pieces, if there's a long-running theme I'm afraid it passed me by.  And in the absence of that connection, I found Twin Primes mildly frustrating – because whenever things were just getting interesting, it stopped and started from the beginning again.

The intermittent nature of the work is a challenge for the actors too, but it's one they generally rise to: the earlier, more comic characters are played broadly but with a pleasing knowingness, while the later scenes display both sensitivity and finesse.  So Twin Primes is a bold and interesting experiment, with a few flashes of brilliance; it's just that, for me at least, the numbers didn't add up to quite enough.