It is dusty, dirty and dark in the underground bunker of our scene. The Great War howls around us: whistling shells drop over No Man’s Land and distant gun fire stutters. We sit on benches under the light of low swinging lanterns, surrounded by canvas and hessian sack walls. Then two voices emerge from the haze, harmonising "Silent Night". It is Christmas in the bunker, and Arthur, Lancelot and Gawain (Hayden Wood, Sam Donnelly, and Jonathan Mathews), boarding school friends who affectionately named themselves for the Knights of the Round Table, attempt to keep their minds from the atrocities above them. Their quick and charmingly pompous public school repartee amuses them – and us – as they tease one another and reminisce on more innocent days.

Soon, the banter gives way to darker tensions, and memories are revealed in seamless transitions from present to past. Gwen is the figure central to Lance and Arthur, a Cornish girl – quite removed from her regal namesake – but adored dotingly by both men just the same. The innocence of these scenes, particularly evoked by Bebe Sanders as Gwen, contrast jarringly with the horrors of the present. It is this innocence, perhaps, that ultimately sanitises the romance, which doesn’t seem as fully realised as some of the play’s other achievements.

Gawain, meanwhile, is transfixed by a woman he claims to have seen whistling in No Man’s Land. Here, Morgan le Fay, the curious and magical shape-shifting sorceress of the Arthurian legend, comes to life. Is the enchanting French woman Gawain begins to meet a reality, or a necessary figment of his imagination? The tenderness and quiet affection of Sanders and Matthews makes their plot more compelling than the love triangle. It is a bumbling kind of romance, sweet and awkward, and I cared far more about its inevitable betrayal than I did of that between Arthur and Lancelot.

By contrast, Gwen seems a distant figure, and perhaps that's the point – she’s far away, home in Cornwall, existing, as Morgana does, more in imagination than reality. The importance of fantasy to quell the frightened minds of the men arises poignantly in the play’s final scenes, but the developing tension, both internal and in the relationship between Arthur and Lancelot, feels otherwise underplayed. Far more expertly realised is that of Gawain, and Lancelot’s brutal reveal of the truth of his fantasy ‘fairy’ woman is a harsh reminder that, as Arthur says, "Sometimes it’s kinder to keep the story alive."

The Bunker Trilogy is a Fringe favourite of mine, but Morgana is, perhaps, not the strongest of the three. However, it succeeds as a richly imagined version of the Arthurian legend, with nuanced and compelling performances.