O’Flaherty’s three-act tragedy, set on an Irish-speaking island, was performed on the Abbey Theatre stage in 1926. The play centers on two brothers competing for the same woman whose choices have disastrous consequences for all involved. As with all of O’Flaherty’s great works from the 1920s and 1930s, Darkness challenges social, cultural, and moral conventions and presents a searing critique of social life in the Irish Free State’s initial years. This scholarly edition includes the text, contemporary reviews, illustrations, and a substantial critical introduction by Ó Conchubhair.