Jay Taylor’s debut play The Acedian Pirates was shortlisted for the inaugural Theatre503 Playwriting Award in 2014. Now, two years later, it’s come back home in dramatic, devastating style, to confront one of the oldest questions in history: why do human beings go to war?

Jacob, a young man newly transferred to the Intelligence division, sits in a lighthouse with his fellow soldiers, listening to the sounds of a mysterious woman being interrogated on the floor above. We don’t know where they are; we don’t know who they’re fighting or what they’re waiting for. We don’t even know when the story’s set – it could just as easily be ancient past, present day or dystopian future. And somehow that doesn’t matter; this is, after all, just one more war in an endless series of wars, so who cares where or when it’s taking place?

Besides, it’s another question that interests Jacob: why they’re at war at all. Why, he wonders, is he called a hero for killing fifteen strangers just because they wore a different uniform to him? What is it that keeps them all there, on that island, year after year? The other men answer in meaningless rote responses – that they’re there to fight, to help, to do some good – but even they seem unconvinced. In frustration, Jacob finally turns to the only other person who might be able to answer him: the woman upstairs, the one nobody’s seen but who all nonetheless firmly believe to be “everything”.

This isn’t a particularly easy play, either in its heavy subject matter or its intellectual tone; I’d recommend brushing up on your Greek mythology before leaving home. Yet despite the sophisticated vocabulary and the numerous classical references, Jay Taylor’s writing still captures the natural speech patterns of a bunch of men who’ve been cooped up together for a long time. Light-hearted banter, explosive rage and wistful nostalgia combine in a script that’s not only totally believable but also brilliantly delivered by an excellent cast.

Cavan Clarke leads the way as Jacob, skilfully managing his character’s transition from youthful arrogance to the very brink of madness. His quiet thoughtfulness is matched by that of Marc Bannerman as Bull, a man of so few words that when he does choose to speak, we listen. Meanwhile Ivan (Matthew Lloyd Davies) and Bernie (Andrew P Stephen) rarely shut up, constantly full of stories from the glorious past; whether they’re actually their own stories is neither here nor there. Rowan Polonski is the oddly charismatic commanding officer Troy, who seems quite mad but may just turn out to be the sanest of them all, while Sheena Patel is a refreshingly sharp-tongued damsel in distress.

Trapped as we are within the lighthouse – beautifully imagined by designer Helen Coyston – there’s a simmering tension in Bobby Brook’s production that has little to do with the fear of physical harm. Lighting and sound effects from Cat Webb and Simon Slater give us a powerful impression of the conflict raging outside, but the real struggle is unfolding within these walls, and the only question is how and when it’ll reach its climax.

The Acedian Pirates feels particularly relevant at a moment in our history when the habit of parroting dangerous ideologies without hesitation seems to be on the rise, and those who dare to disagree are accused of being unpatriotic or disrespectful. The play doesn’t offer any answers to its central question, but perhaps that’s because there simply isn’t one to offer. Or rather there are too many; the sad fact is we’ll always find a reason to make war against each other – even if, after a while, nobody can quite remember what it was.