Colm Tóibín’s first play deals with the events surrounding the riots at the Abbey Theatre in 1926, during the production of Sean O’Casey’s The Plough and the Stars. The story is told by O’Casey himself, observing the ebb and flow of reactions to his work, from loyal support to violent condemnation.

Is it possible to create credible images of people such as W. B. Yeats, Lady Gregory, Lennox Robinson and F. J. McCormick with historical accuracy and dramatic interest? The answer is clearly no, because the author has not seriously attempted it. He has instead filled his version with caricatures, and provided singing but single notes for their interpreters. True, he seems to change his mind and style in the closing scenes, when solemn thoughts are unfolded; but that is too late to change the thrust of the play.

So we have O’Casey (Donal O’Kelly) defending his script against its critics, and the lofty but calculating Yeats (Sean Campion) delivering the famous “You have disgraced yourselves again” speech. There are the authoritative Lady Gregory (Derbhle Crotty), the effete director Robinson (Karl Shiels) and several famous actors (here by Karen Ardiff and Caitriona Ní Mhurchú). Walking clichés all, the multi-role cast nevertheless slot neatly into their allotted places, rather like a jigsaw with some pieces missing.

If the play itself is something of a maze of variations on an old theme, the treatment still invites consideration. Niall Henry directs with the knowledge that realism won’t work here, and deploys his talent for metaphor to some effect. Mrs Sheehy Skeffington is about eight feet tall; O’Casey at one point appears in pierrot costume; there is a little music-hall. But while these catch the eye, they are not harnessed to any dynamics inherent in the play, and ultimately add to a general incoherence.

The ending is, as already indicated, a solemn retrospective, and only here is Colm Tóibín’s undoubted ability to write impressively in clear evidence.

But it is not credible dialogue, and the writer has yet to make that notoriously difficult leap from novel to stage.