What do you get when you cross a 19th-century playwright impresario with a ferociously talented 21st-century, New York dramatist?

If the former is the fantastically successful Irishman, Dion Boucicault, a producer and writer of “sensation dramas”, who had hits in London and New York, and the latter is Branden Joseph-Jenkins, a ferociously talented Pulitzer-nominated playwright who has become a master of writing the unexpected, the answer is this astonishingly inventive unravelling of America’s knottiest issue, racism.

Those who saw Joseph-Jenkins’s office play Gloria at the Hampstead last year will know just how unexpectedly — and brutally — the first act ended. In this earlier play, first seen in the UK at the Orange Tree in Richmond, he audaciously places himself at the centre of the drama.

BJJ, as the cast list in the programme calls him, is superbly played here by Ken Nwosu. He may be black, BJJ tells us, and he may be a playwright, but he hates being called a black playwright.

“I can’t wipe my ass without someone trying to accuse me of deconstructing the race problem in America,” he says, before transforming himself into a white, 19th century slave-owner and, in the process, launching his play, and us, into Boucicault’s 1859, Louisiana-set potboiler.

It’s about slaves and their owners — and the “octoroon” of the title, Zoe, a white girl who is one eighth black. And it is here that Joseph-Jenkins’s play follows the plot of Boucicault’s play but always one step or more removed.

Meanwhile, modern American anxieties about race are a constant presence. Skin colour — or perhaps a better term is “skin identity” — becomes a repeating motif as the mixed-race, black-and-white cast black-up to play a slave, white-up to play a slave owner and red-up to play an indigenous American.

Now, although BJJ describes his 19th-century counterpart as nearly forgotten, this is not the first time Boucicault’s work has been manhandled into being suitable fare for today’s audience by a modern playwright.

When he was at the National, Nicholas Hytner revived Boucicault’s farce London Assurance, for which he called upon Richard Bean to beef-up the jokes and, in particular, to subvert the Victorian antisemitism in the play.

But that was trifling compared to what’s going on here — a reminder that history is a thing of the present not just the past. Meanwhile, Ned Bennett’s production is a triumph of tone. It revels in the comedy and melodrama of Boucicault’s original but also injects a searing naturalism, particularly with respect to two fearful and defiant slave-girls, Minnie and Dido, stunningly played by Vivian Oparah and Emmanuella Cole.

But, for them, everyone else here is a construct that exists to depict an idea, which inhibits somewhat our ability to care about their fate. It does all this while subverting just about every theatrical convention in the book. Sudden lighting changes persistently vault us back and forth between BJJ’s century and Boucicault’s.

Those who saw Gloria will not be surprised by the invention. But the sense here is that BJJ may have surprised himself. For, although “deconstructing the race problem of America” is the last thing he wanted to do, that is exactly what he has done.