NEIGHBOURHOOD WATCH Tricycle Theatre, London NW6

A middle-class community, dissatisfied with the way the police are dealing with the anti-social behaviour on a sink estate, takes the law into its own hands and turns vigilante and fascist. Alan Ayckbourn’s portrait of the Big Society is potentially one of his best black comedies; but he loses his way in the second act and spoils it with outright caricature, unlikely events, and an unnecessary coda after the play has finished. The opening monologue (which gives away the ending) should be cut. The more real the situation is, the better the comedy is. Terence Booth as the ex-security officer gets it right: he is totally farcical yet totally real.