By Alan Harris.
Lighthouse keepers Howell and Griffith are posted to 6 weeks on the Smalls - a desolate rock 20 miles off the Pembrokeshire coast.
But the two men share a past.
Because of what happens next, lighthouses would never again have only a crew of two.
Based on a true story.
Ifan Huw Dafydd
Directed by James Robinson
Alan Harris is a Welsh writer on the rise.
His play A Good Night Out in the Valleys launched the new National Theatre Wales and he's currently working on a commission for the Welsh National Opera.
His first radio play, The Gold Farmer, was broadcast by BBC Radio 3 as part of The Wire season.
In The Lighthouse, Alan's dark imagination has created an eerily compelling and atmospheric ghost story full of mordant humour and gruesome frights.
Two men become trapped in a lighthouse, 20 miles off the Welsh coast.