EVEN a long-established playwright can do with a lucky break.

And that's what Alyn Ayckbourn received with Neighbourhood Watch, a sharp, hilarious black comedy about vigilante justice, which just happens to coincide with the public debate about last summer's riots.

It begins when a fundamentalist Christian brother and sister move to a pleasant housing estate, looking down – in every sense of the phrase – on a crime-ridden council estate.

They enjoy each other's naive jokes and resolve to be good neighbours, but Ayckbourn the master humorist has surprises in store.

There's a misunderstanding about a trespasser and plenty of locals ready to see it as lawlessness gone mad.

But when a garden gnome comes crashing through their window, they begin the mother of all neighbourhood watch programmes.

The estate becomes a fortress with security fences, stocks to imprison offenders, and volunteers patrolling with baseball bats – some of whom really enjoy using them.

It's a dark morality tale rather than a character study but Matthew Cottle and Alexandra Mathie excel as the siblings, matched by the rest of director Ayckbourn's, Stephen Joseph Theatre Company.

There's an indignant local gossip (Eileen Battye) and retired security officer steaming with hatred (Terence Booth).

While an outrageously unfaithful wife (Frances Grey) and her mouse of a husband (Richard Derrington) also get reshaped in the maelstrom.

Even a security clampdown opponent (Phil Cheadle) brims with aggression.

In this his 75th play, Alan Ayckbourn once again links laughter with insight. Here's to him completing his century.

Derek Briggs