It's been two years since 276 Nigerian schoolgirls were kidnapped by the Islamic terrorist group Boko Haram. Though some escaped, and a few have been found, more than 200 of them remain unaccounted for. Their plight continues, but their story has fallen from the front pages.

Theresa Ikoko's play, winner of the Alfred Fagon award for black British dramatists, imagines three such lives in captivity. Three teenage girls, no more than 14, are stuck in a cell somewhere off-map, held by an unnamed terrorist organisation. They sustain themselves by imagining their families back home, still searching, and playing out typical teenage fantasies. Ikoko presses the point that this has become their norm, and, as the girls giggle over sex and gossip about Beyonce and Lady Gaga, you get glimpses of the lives denied to them.

They are a well-balanced trio. Haleema (Anita-Joy Uwajeh) addresses their situation frankly, furtively sharpening a stone knife and plotting to escape, while Ruhab (Yvette Boakye) falls in line in order to secure sympathetic treatment. Taking the hijab and joining daily prayers, she marries one of their captors and conceives a child. The youngest, Tisana (Abiola Ogunbiyi), clings to hope and to her Christian faith, for which she is mercilessly whipped.

Ikoko does something rather daring, and Girls draws a parallel between the terrorists and the patriarchy as a whole. Dependent on them for food and, indeed, life, the three girls collude with their captors, appearing in propaganda videos and sewing the black flags of fundamentalism. Rozanna Vize's design imprisons them in a pink holding pen, aligning their confinement with their gender, and each of their survival tactics – Ruhab's acquiescence, Tisana's resolve and Haleema's defiance – stands as much a stance against a system as well as their actual situation. Patriarchy is a prison, Ikoko insists.

However, as a result, her writing pulls in two directions at once. Girls' characters are both abstract and real. To make points about the media landscape and its portrayal of women, Ikoko affords the three hostages a level of knowledge they wouldn't have. It's not that they're au fait with Beyonce and James Bond, but they understand the Twitter campaigns running in their name and the newspaper coverage of their plight. They are privy to our perspective of their situation. Yet at the same time, Ikoko wants to show the grinding reality of that situation. Elayce Ismail's production, staged in situ, never quite finds a way to have it both ways.

It is, however, passionately played, even if the cast struggle to maintain momentum through the play's short, staccato scenes. Ogunbiyi, in particular, is touchingly restrained as Tisana, holding in tears as her back becomes a mesh of open wounds, and Uwajeh's Haleema is a striking presence as she prepares to fight for freedom. Boakye ensures Ruhab's obedience remains a reasonable response, rather than a personal defeat. An ambitious, eloquent piece of writing, Girls is a mark of Ikoko's promise, even if it hasn't yet found its form.

Girls runs at the HighTide Festival until 17 September, then at Soho Theatre from 27 September until 29 October.