Irish writers have always shined a bright light into the darkest parts of human nature. In this sense Eugene O’Neill, although born in New York and raised in Connecticut, is an Irish writer of the first order, because literally nothing escapes his lighthouse gaze.

Widely regarded as America’s greatest playwright, throughout the last two decades his major works have been brilliantly and even obsessively revived by the Irish Repertory Theatre, with unforgettable drama being the usual result.

In Beyond the Horizon, a deeply moving tale of false starts and might-have-beens that seems to have sprung directly from the global Irish experience, O’Neill is at his best as an excavator of the private and unforeseen costs of making all the wrong decisions for all the right reasons.

First performed in 1920, when it won the young playwright the Pulitzer Prize, the story retains a nursery freshness that arises from its biblical storyline.

The first full-length play O’Neill wrote, right from the start of his career you can hear distinctly that saturnine note that arises from his having the rare courage to look at the world face on, unflinchingly.

The play focuses on two brothers, Andrew and Robert, who enjoy a rare degree of fraternal respect and even friendship. As the play opens Robert, a poetic dreamer, is about to go off to sea, while the homebody Andrew simply looks forward to marrying his childhood sweetheart Ruth and working hard on the family farm for the rest of his days.

But then something unexpected happens. Ruth reveals she really loves Robert, giving him a reason to stay home and shattering Andrew’s modest dreams of starting a family on the farm.

The two brothers switch places. Andrew goes to sea and Robert stays home to work the farm. What had looked like the natural order is then overturned with fateful and far-reaching consequences for them all.

So it’s a melancholy tale, Beyond the Horizon, but life often is too. What makes O’Neill such a devastatingly effective playwright is his refusal to look away from the every day disasters that can befall any of us all too quickly, even with the best intentions.

It’s what’s fascinating about O’Neill too. What’s distinctive about O’Neill’s plays is how spiritually Irish (rather than American) his view of life’s real possibilities are.

The Irish can be said to spend their lives anticipating tragedies that have yet to strike, but to Americans the future can be a source of endless optimism. O’Neill stands with his contrary Irish forbearers in this regard, and it’s part of the secret of the enduring power of his work.

As Robert, actor Lucas Hall is believably at sea in a life on land he never planned for himself. As his brother Andrew, actor Rod Brogan gives tender expression to the conflicting impulses that have given his life its unexpected character.

But the night belongs to actress Wren Schmidt, who plays Ruth, and whose tragic journey is the heart and soul of this production. Beginning as a bright young thing with her whole life ahead of her, she ends the night cowed and crushed by too much heartache.

Schmidt never misses a note on the long road from love to loathing, but the sheer force of O’Neill’s imaginings seem to hit the young actress with the same intensity they hit his creations. By curtain she looked shell-shocked and spent, a sure sign that the emotional wallop this play delivers is more than just skin deep.

Beyond the Horizon is about losing the courage to live the life you’ve dreamed of – and the steep cost that making safer choices can result in.

Set on an open road, one that cruelly has not been taken, the play is at its best when it focuses on the individual costs that bad decisions (an O’Neill obsession) create in all the years that follow them.

Ciaran O’Reilly directs lucidly throughout and is to be thanked for reviving this absorbing early play.

The production has uneven moments when light comedy involving the old sea dog Captain Dick Scott seems to belabor the play’s dual themes of choice and consequences, but the pace revives after the early act one banter and the work turns into something increasingly rich and strange.

O’Reilly has become an ideal interpreter of O’Neill’s work because he brings both an Irish and American sensibility to his staging, and in the process he has revealed something arresting about the writer -- O’Neill is an Irish playwright, at least spiritually because he stands at all times with his maimed Irish forbears.

Beyond the Horizon plays at the Irish Repertory Theatre. 132 West 22nd Street, until April 8. For tickets and showtimes visit www.irishrep.org.