Robert Hanks: Undercover acting knocks spots off the traditional kind

The Week in Radio

The two best pieces of acting on the radio this week both came in an edition of Crossing Continents (Radio 4, Thursday) on the Liberian orphan trade. One of the consequences of a couple of decades of civil war in Liberia has been a steady supply of children who need taking care of – because they're orphans, or because their parents can't make ends meet poverty. Since western countries, the US in particular, have a steady supply of would-be parents, canny middlemen have taken advantage of the situation, setting up adoption agencies. Nadene Ghouri and her producer visited an agency in Monrovia, pretending they were a Canadian couple looking for a child.

Runner-up for performance of the week was "Bishop" Ed Kofi, the agency's head, for his impression of Christian bonhomie. Asked how much an adoption would cost, he was so busy chuckling at the bountiful ways of Providence that he could hardly get out the answer: "It's free. It's free, it's free." But you couldn't help feeling that he'd run through this script before. The winner was Ghouri herself, for a portrait of barely contained maternal desperation that contained flashes of improvisatory brilliance: "If I want to adopt one tomorrow – which [slightly hysterical giggle] I know I'm going to – how much will it cost us?" Even better was the way she pushed the money question, pretending it was her mean old husband who wanted to know: "Go on, put him out of his misery, tell him how much." The answer turned out to be $5,000, which is almost the same as free. In a way, the performance was counterproductive. Ghouri had uncovered a dispiriting story, of loving families wanting to do their best for hungry children being conned into giving them up for ever. But the programme left me with a buzz of pleasure and admiration.

You don't get acting like that in the actual plays on the radio, especially not these days, when everything feels like it's being done without rehearsal. My current bugbear is Jack Woolley's prolonged descent into dementia in The Archers – a long overdue attempt by radio to understand the difficulties associated with an affliction that is all too often swept under the carpet. Yeah, I get that, but if I hear him putting on his little-boy-lost voice one more time, hooting like an anxious Clanger with a Stirchley accent, either I or the radio will be going through the window.

When I say that I have no complaints about the acting in Tamburlaine: Shadow of God (Radio 3, Sunday), you can take it as praise of the highest kind. John Fletcher seems to have made something of a speciality of turning epic military campaigns into somewhat sardonic radio dramas. Back in 1991, I loved a play of his called 'Russia', about British troops fighting with the White Russians in the aftermath of the First World War, and straggling to safety halfway across an inhospitable continent. More recently, Radio 3 did his version of 'The Sicilian Expedition', based on Thucydides (now I think of it, Russia was really an updating of Xenophon's 'The Persian Expedition'). 'Tamburlaine', based on the last years of the 14th-century conqueror, had some epic moments early on – descriptions of a massacre (including pyramids of heads, a whole family scalded into statuary by molten lead pouring from a burning roof) were beautifully done. But with the entrance of an Arab philosopher and a poet, it quietened down too much: the confrontation between dictator and intellectual has been done before. Fletcher has a rich and eccentric imagination, and he's more at home conquering new empires than treading familiar ground.