High summer and it’s blockbuster time. The Donmar’s latest show is by the acclaimed Nick Payne, whose play about string theory, Constellations, wowed the West End last year. Constellations niftily incorporated its subject matter into its formal structure. What does that mean? It means the storylines multiplied like an exploding atom until an infinite number of possible endings came crashing through the space-time continuum and collided with the viewer’s patience, bundling it down a black hole.