Sometimes it's best not to revisit favourite old haunts. In belatedly adapting his superb 1995 novel for the stage, Hanif Kureishi has done neither himself nor his subject matter many favours.

What was promised as a trenchant exploration of the roots of Islamic fundamentalism in our post-7/7 world ends up as a listless trudge through a series of tired scenes.

It's the academic year 1988-9 and young Shahid Hasan has moved from Sevenoaks to attend college in London.

Sensitive, curious and with literary aspirations, Shahid is attracted to — and subsequently adopted into — a group of Muslim “brothers” whose aim is to tackle the racism they see all around.

Yet with the furore surrounding the publication of The Satanic Verses and the subsequent fatwa pronounced against Salman Rushdie, the group's politics become far more hard-line, and the appeal of Shahid's stimulating — in every sense — lecturer Deedee that much greater.

In a lucid and cogent eight-page mini-essay that introduces the printed playtext, Kureishi outlines his arguments about liberalism and fanaticism, language and censorship with far greater subtlety than he manages in two hours of over-simplified drama. We try to convince ourselves that Shahid is a young man desperately torn between the cool rigour of religion and the sensuality of sexual and intellectual self-discovery, but despite an appealing central performance from Jonathan Bonnici, we just can't.

For far too long, Shahid seems a placidly contented, under-involved day-tripper between these two poles of his life.

Jatinder Verma's uninspired direction for this co-production by the National and Tara Arts has the action shoehorned into a narrow set bounded by screens of video projections that do little to establish any clear sense of changing location.

He's not helped by the fact that Kureishi has failed to translate the comic astringency of his prose, and to bring the supporting characters to anything like fully realised life.

Riaz (Alexander Andreou), leader of the brotherhood, seems more buffoon than possible visionary, and the best we have for comic relief is Shahid's older brother Chili (Robert Mountford) lurching about like he's auditioning for a sequel to Withnail And I.

Deedee (Tanya Franks) gets to wear nice leggings and smoke a few spliffs, but there's little else to suggest she's a serious career option for Shahid. A great disappointment.