King David, Man of Blood, by Fraser Grace, Mercury Theatre, Colchester, until June 10

INNOVATIVE as ever, the excellent Mercury Theatre Company have pulled off another coup.

Fraser Grace is a name to remember. His remarkable new play, which he has helped Mercury artistic director Dee Evans bring to the stage, is something to remember too.

It is, in Grace’s own words, “a terrible, diabolical comedy”. Which doesn’t mean he’s dismissing his own work.

Terrible things happen in it, due only in part to the diabolical influence of Lucifer. It’s not a comedy in the old sense of a happy ending, nor is it in any sense light – but it is very entertaining and at times very funny.

Too many modern plays are let down by poor dialogue, but here the verbal exchanges fairly crackle.

Right from the start I found myself wishing to note down or remember some of the many excellent quotable lines. So much so, I was glad to find complete scripts on sale in the foyer afterwards.

The story, based on Old Testament accounts, depicts an arrogant and cruel David. His obedience to God takes the form of serial war-making and mass slaughter.

This is not a God many Christians - or Jews - might recognise today, but that’s part of the point.

The Almighty is portrayed cleverly – offensively, perhaps, to some – by both Andrew Neil and Christine Absalom as a sharply white-clad modern couple.

They are like an urbane, reflective middle-class chief executive and his bored wife, amusing themselves by gambling with Lucifer.

Their wager, which frames and drives the main action, is a little more complex and subtle than a simple battle for David’s soul.

Lucifer, brilliantly played with obvious enjoyment by Tony Casement, becomes David’s exquisitely manipulative servant.

For once, the devil doesn’t have quite the best lines or even the cruellest. As he finally admits, for casual brutality he is outdone by God.

The fact that this may still shock some audiences just shows how vital some of the moral questions the play explores still are. Of course, at the heart of it all is the figure of King David himself.

It’s a towering, troubled and troubling role. It demands an intense, intelligent performance. It gets a great one from David Tarkenter, who is fast becoming my favourite actor.

His dynamic display reaches a stunning climax in a blockbuster near-final scene.

That one grim scene perhaps carries a little too much weight, too many twists for each to get its full value. The emotional demands made on Clare Humphrey as the tragic Bethsebe are extreme, but she remains rivetingly watchable throughout.

This is not quite a flawless play. But it is a very, very good one. It will surely enjoy many future productions. It may never be done better than this.

AIDAN SEMMENS