Naturalism, at its best, carefully communicates the subtle stories behind the realistically portrayed events on stage. Those who attempt to write naturalistic plays know how difficult it is to create a coherent experience for their audiences: a single missing or underplayed aspect will push the play off balance and the audience into boredom.Now try improvising a naturalist play. Tricky? What took Chekhov several drafts is a mammoth challenge to achieve spontaneously on stage.Tom and Noeleen are about to throw "the worst dinner party imaginable." Their guests are comfortable chatting about bees and whether they really need their little toes (it turns out they could live without), but when the underlying tensions rear up around the table, the characters don't know how to cope. Improvising the content of a pre-decided structure, the five actors of Exterminating Angel depict a dinner party in which no one can leave the room, for some mysterious reason. Unfortunately, the mysteriousness of this reason makes the increasingly melodramatic actions of the characters seem random.This performance was a drama-school exercise rather than a fully formed play. I left with the feeling that a simple explanation of what the company were trying to do would be much more interesting than watching the final result. The company have a lot of work to do before audiences will understand and enjoy this work as much as a fixed-script play.Theatre is a spectator sport, but this performance lost sight of communicating with the audience because it was caught up in its self-imposed challenge of improvised naturalism. This cast simply aren't ready to take on that challenge in front of an audience. Improvisation lends itself to incoherence or melodrama, and that's exactly what happened on the first night of Exterminating Angel: it was a little silly, and it didn't make sense.