Saw this in preview on 19 April.
This play is rarely performed, I suspect because it has a "reputation" born of WB Yeats dismissing it for his own personal reasons in 1928. When it originally played in London in 1929 it was compared adversely to other WW1 plays of a more realist bent which had aired just before. And when it eventually came to the Dublin stage, its original intended showplace, it lasted 5 performances. But this is a great play by an Irish master playwright, Sean O'Casey, and this production is masterful.
The play itself is in 4 acts, the second act being a "dream sequence". But what a dream - just behind the Front in WW1. It seems it was this second act that WB Yeats so despised first because WB didn't think WW1 should be depicted on stage by those who hadn't been there and second because "impressionist theatre" was avant garde, and not to his taste. Well he was worng on both counts. I will not spoil the play by relating any of this act. Suffice it to say that it is both mind-blowing and central to understanding how those who went into the War felt disconnected from their loved-ones when they returned. Once you have witnessed the events on stage (and, fear not, there are no serious blood and guts), you will understand why.
The rest of the play relates the story of a Gaelic football hero cheered off to war by his loved-ones and misunderstood and misplaced on his return. Along the way O'Casey takes aim at established religion, domestic violence, militarism, authority, healthcare and disloyalty (to name the main ones) and scores a hit every time.
In the 1920s and 30s this play expressed very uncomfortable ideas. Today, I think most of us would agree with the points made. But those points are no less valid because they are more familiar to us and they are made in the context of a story which engages and saddens us. Do not miss it.