Sorrows and Rejoicings, Tricycle Theatre, London

It begins with scene of pure Ibsenite exposition, carefully laying out the back story – how Dawid left this house "17 years ago", how these two post-funereal women are wife and upcountry mistress, how he always said he would return. And then the history continues. And continues. And continues. By the end of this hundred-minute requiem, you have watched a play written entirely in the past tense.

Maybe this is no accident. We all worried what would happen to the playwrights who in the Seventies became the standard bearers against the totalitarians. What could they write about once freedom became theirs? Some, like Havel, shifted into real politics, others continued writing. We flocked to their first post-liberation plays, eager to join the rejoicings, only to discover that, without the added frisson of agitprop, they weren't quite the writers we once took them for.

And Athol Fugard is surely the Grandaddy of them all, the grizzled face of anti-apartheid theatre: Sizwe Bansi is Dead, Master Harold and the Boys, The Island, all memorable rallying cries, true stand-up-and-shout theatre. But his story of Dawid's exile on the Finchley Road, his despairing alcoholism, impotence and flight back to the Karoo to die, is like a metaphor for the flight of Fugard's own creative inspiration. Every scene is viewed from the past, composed of long elegiac speeches where characters dissect and then perfectly sum up their emotions. It's beautifully acted – by Denise Newman as soulful mistress and Jennifer Steyn as etiolated wife – but feels more like a love poem to the good old bad old days.

Where novelists like Coetzee and Brink have masterfully set about examining the new equations in South Africa, Fugard is still writing about back then. Or at least he's writing about someone who is steadfastly clinging to Back Then.

That, of course, is the biggest plot hole: while the play is nominally set in 2000, we're repeatedly told that Dawid chose exile "17 years ago", about 1983. But Mandela was released in 1990. Why did he not return until 1999? Maybe this is supposed to be The Big Revelation but the "shame" explanation was limp. Flight in the face of repeated police searches and 180-day interrogations, was hardly a matter of shame. And the return of the exiles was a victory parade. I think Fugard knows it's limp as well, hence the alcoholism and mumps-induced sterility. It all seems a little desperate.

By now, you're probably thinking there's more than enough here for an interesting night out. The trouble is that the characters simply don't interact: they soliloquise in front of each other, never interrupted. Their perorations voyage deep into the deserts of perfectly formed self-analysis. They reach the end of the story, stop and then it's someone else's go. No one gets a word in edgewise, no one even tries. You cannot compose a play entirely in the pluperfect. The result is numbingly dull.

To 20 April (020-7328 1000)