THE secret marriage of a playboy prince to the shop girl who is carrying his child triggers an Establishment cover-up that involves a spate of horrific murders.

This tangle of intrigue, ruling class ruthlessness and barbarity reaches the very top of British society, catching in its slipstream the highest in the land. It proves that the rich and powerful will stop at nothing when their interests are threatened.

The identity of Jack the Ripper will probably never be known. But this play by Brian Clemens, based on the notion that the Duke of Clarence’s murky secret was at risk of being exposed by a group of prostitutes – and they therefore had to be killed – seems entirely plausible.

Andrew Paul floats to the top of this swamp of corruption as royal physician Sir William Gull. He is the very personification of well-heeled evil, determined to protect a system now under threat from the unwashed masses.

The royal family and even the future of the British Empire are at stake and so the murder contract is given to Gull’s coachman John Netley, played with a growing vileness by Michael Kirk.

But Sherlock Holmes (Samuel Clemens) is fearless in his pursuit of the truth, even daring to act against his own Freemasons lodge which has been instrumental in hatching the ghastly plot.

This is truly brilliant stuff. The final confrontation involving prime minister Lord Salisbury (Greg Fitch) becomes an absolute classic denouement and one that would perhaps have even the great Poirot himself nodding in approval.

Director Patric Kearns interprets the relationship between Holmes and Watson (George Telfer) as being more relaxed than tradition usually dictates, the latter often appearing to be the real power behind the throne.

A succession of dry exchanges provides some welcome comic moments that bring a lighter touch to what is essentially an exceedingly dark tale.

And it all adds up to make a gripping piece of theatre that shines a torch into the murk of Whitechapel alleys that still, to this day, refuse to give up all their hideous secrets. It runs until Saturday (July 25).

John Phillpott