AS we come to the end of Black History Month, Glasgow-based dramatist May Sumbwanyambe, can be sure that, in his new play, Enough of Him, he has made a particularly excellent contribution to Scotland’s reckoning with its too often neglected role in the horrors of the transatlantic slave trade.

Set in Perthshire in the late-18th century, the drama (which is a co-production between the National Theatre of Scotland and Pitlochry Festival Theatre) considers the path-breaking legal case of Joseph Knight, the Black slave who won ahis freedom when, in 1778, he established at Perth Sheriff Court that slavery had no status in Scots law.

This is no legalistic courtroom drama. Rather, Sumbwanyambe offers us a brilliantly imaginative leap into the lives of, not only Knight, but his nominal “owner” Sir John Wedderburn, Margaret Wedderburn (the slave owner’s wife), and Annie Thompson (the servant in the Wedderburn’s mansion at Ballindean, who would become Knight’s wife).

Much is known about John Wedderburn, who rebuilt his family’s fortunes on the backs of African slaves in the sugar plantations of Jamaica, after his father, Sir John Wedderburn, 5th Baronet of Blackness, was executed for his part in the Jacobite uprising of 1745. By depressingly predictable contrast, Joseph Knight disappears from the public record the moment he is freed from enslavement by Wedderburn.

Sumbwanyambe’s play is set in the period before Knight gained his freedom. At Ballindean, the memories the men carry of the savagery of the slave colony in Jamaica are so traumatic that, to quote the great poet William Blake, they “run in blood” down the mansion’s walls.

Knight is wrestling with both the trauma of what he experienced in transatlantic slavery and his sense of guilt that other slaves suffered considerably worse than he did. As Omar Austin’s anguished, dignified, witty Knight tells Annie (played by Catriona Faint): “It’s not all oceans and paradises in my head.”

The play expresses brilliantly the complexity of the distorted relations between “master” and slave. Wedderburn (played with tremendous, teetering arrogance and distressed rage by Matthew Pidgeon) congratulates himself on his supposed good treatment of Knight, but he cannot expel from his mind memories of the terrible sexual sadism that drove his relations with female African slaves in Jamaica.

Director Orla O’Loughlin’s sharp, tight production is blessed with excellent and minimal period design, including a large painting of a Scottish landscape that, through technical ingenuity, also serves a Blakean metaphorical purpose. John Pfumojena’s musical score weaves together the West African and the Scottish with delightful intelligence.

This is, then, both a great history play and a brilliantly creative work of theatrical fiction. The depth and intricacy of its depictions of desperately mangled, horribly unequal human relations raises it well above the well-intentioned theatre of liberal polemic. Indeed, its captivating complexity makes it not only a stunning indictment of the moral poison of racism, but also a work of extraordinary emotional, psychological and political immediacy.

The National: Sam Stopford, Benjamin Osugo and Francesca Hess in AlföldSam Stopford, Benjamin Osugo and Francesca Hess in Alföld

There is a similar dramatic sophistication in Joe McCann’s (possibly semi-autobiographical) Alföld (the title is from the Magyar word for “lowlands”). The piece – which transfers to the Traverse Theatre, Edinburgh next week – is directed for the Oran Mor lunchtime theatre A Play, A Pie and A Pint (PPP) by Dominic Hill, artistic director of the Citizens Theatre, Glasgow (the building of which is still undergoing its long and substantial renovation).

McCann is a Black writer based in Glasgow. His wife, like the female protagonist in his play, is (the show’s programme notes tell me) called Virag. One can’t help but wonder if this unsettling drama about a young couple (a Black Scottish man and a white Hungarian woman) who are forced to share their train cabin with a somewhat sinister stranger (who is white and Hungarian) is inspired by real events.

Whatever the drama’s origins, it certainly proves – as, in fairness, do many of the plays staged by PPP – that lunchtime theatre doesn’t have to be light and disposable. Nuanced and complex, this self-proclaimed “dark comedy” draws us into the spiky and uncertain relations between Jake (the Scotsman) and Virag, as, on the second anniversary of their difficult marriage, they head down to the titular Hungarian lowlands to visit her family.

Virag’s penchant for brutal mind games clashes discomfitingly with Jake’s aversion to conflict. The over-familiarity and oddness of their unwanted travelling companion, Bela, adds an incendiary element to the mix.

Played at the Oran Mor on a makeshift thrust stage (with the audience seated on three sides), the piece generates a transfixing sense of tension. The antagonism between Virag and Jake renders them incapable of sticking by their rules of engagement as they play along with Bela’s increasingly outlandish suggestions.

THIS is contemporary Hungary, an imperilled democracy that has had the far-right demagogue Viktor Orban as its prime minister for 16 of the last 24 years. Little surprise, then, that lurking beneath Bela’s disingenuous, oily bonhomie (like Harold Pinter’s “weasel under the drinks cabinet”) is a pernicious, racialised nationalism.

In what is a frighteningly good performance, Sam Stopford plays the erratic stranger with the capriciousness of a Pinter character and the inveigling nastiness of the Devil in Dennis Potter’s Brimstone and Treacle. Francesca Hess is compelling as Virag, a woman who – in her simmering-to-boiling frustrations with her marriage – is attracted to emotional and physical danger as a moth is attracted to a flame.

Benjamin Osugo’s Jake is sympathetic and convincing as a somewhat diffident young man with a troubled childhood (one also had to admire his unflustered professionalism during Tuesday’s performance, when some too easily shattered stage glass left him standing with, rather than a jagged weapon, little more than the label on the neck of a bottle of wine).

Unintentionally comic prop failure notwithstanding, this is an excellent 50 minutes of theatre. As one would expect of director Hill, there is not an extraneous moment in what is a subtle and intense production.

Enough of Him tours until November 19: nationaltheatrescotland.com Alföld plays the Traverse Theatre, Edinburgh, November 1-5: traverse.co.uk