My Children! My Africa! (Trafalgar Studios)

Athol Fugard's belief that the pen is mightier than the sword is tested – and found wanting, for some at least – in this stirring, bitter account of apartheid-era South Africa.

The roots of the problem are neatly summarised in an exchange of pleasantries between the contestants in an inter-racial school debating contest. White teenager Isabel proudly tells black student Thami that she's third generation. He responds that his own family history stretches back 100,000 generations.

And his decision to embrace a revolutionary response to his country's injustices spells the end of his long and fruitful relationship with Mr M, his beloved teacher and counsellor.

Edda Sharpe is credited as accent coach for this production of My Children! My Africa! and has clearly had great success with all the cast, at least to an untutored ear. Rose Reynolds crackles with energy and zest for life as Isabel, the jolly-hockey-sticks young woman who hates to lose. Her glowing enthusiasm in the first half is perhaps stronger than her angry and bewildered persona later in the play, but this is a fine performance from an extremely engaging young actor.

Devoted teacher Mr M is played with brimming emotion by Anthony Ofoegbu, whose one fatal error of judgement wipes out a lifetime's work. Nathan Ives-Moiba is Thami – Mr M's most promising pupil – whose presence and stature really do give the impression of a student with the heart and intelligence to become a future leader for South Africa.

Each performer gets at least one crack at a long monologue, and while they all embrace the challenge with spirit, these long, reflective spells do serve to slow down the play's momentum. The narrative itself is not quite strong enough to sustain such a lengthy production, but the quality of the performances maintains the show's intensity.

Nancy Surman has created a thoroughly chilling set that's caged in barbed wired and looks much more like a prison than a school. And the 'Whites Only' signs still retain their power to shock. Lighting designer Jack Weir has embraced the darkness at the heart of the play with his use of shadows and spots, and sound designer Erin Witton creates an uneasy tension with musical distortion and sinister sound effects.

Direction is shared by Roger Mortimer and Deborah Edgington, who have created a powerful and at times intensely moving account of political and personal anguish.

My Children! My Africa! runs at Trafalgar Studios until 29 August. For more information or to book tickets, click here.