THE playwright Caroline Bowder knows how to stretch her actors. Aurora Adams has the unenviable task of playing the Virgin Mary, first as a statue and then as a vision. Sixteen-year-old Guillaume Gougeon plays the disembodied spirit of an embryo in limbo. Northfield End TC's Conversations with Mary is certainly not a naturalistic play.

Bowder knows how to stretch her audience, too. The 70-minute piece is almost unremittingly sombre. It is a reflection on the changing attitude of the Roman Catholic Church to stillborn children between the 1970s and the present day. Maire (Mary Tynan) is a young, pregnant, unmarried woman in rural Ireland, where she is treated with cold moral disdain by her family and her church. We meet Michael, the father of her unborn child (Matt Lord), in unrepentant middle age.

Maire loses her baby late in the pregnancy. She bears her grief through decades in which the austere teaching of the Roman Catholic Church is that children who die unbaptised dwell in the cheerless and godless state of limbo.Only in later life does she find a man who treats her with kindness (Tim Styles). By this time, the Church has changed its teaching. According to the play, this is because the Virgin Mary had a word with Pope Benedict XVI, having had her heart softened by Maire's unborn son, Tom.

The problem with the play is its lack of dramatic tension. The story is presented as monologues and conversations with imaginary presences. It is only toward the end, after nine painfully slow scene-changes, that two credible characters engage with each other. The scene that we really want to see, in which Maire has a showdown with her feckless former lover, is alluded to but not dramatised.

A drama in this style can be engaging if the language is rich and interesting enough to hold an audience, or if the anguish of the story is leavened with humour. But the playwright chooses a language that is bare and staccato, and there is no wit to vary the pace. The only exception to this is a dance with which the Virgin Mary introduces Tom to the rapture of paradise, which is very funny (not entirely intentionally). Perhaps trying to imagine yourself in heaven when you are in a bare studio space above an East End factory was too much of a stretch for the imagination.

Informative, yes; impassioned, yes; entertaining, no. But maybe that was too much to expect of a play about limbo.

Conversations with Mary started its run at The Rag Factory, east London. It continues at St Silas's, Islington, from 12 to 13 April, then at the Etcetera Theatre, Camden, from 15 to 20 April, and finally at St Mary's, Henley-on-Thames, on 2 May.

www.northfieldendproductions.com