There's an extraordinary emotional concentration and intensity of focus in a piece like Purgatory, one of Yeats's last works that hauntingly demonstrates the benefits he derived from turning for a model to the symbolical starkness of Japanese Noh drama where the deceased interact with the living and where there is much that chimes with Yeats's belief that the dead are forced to "dream back" the pivotal events of their earthly existence until they know at last their consequences.
Presented in a production by Diana Maxwell that has all the austerity if not quite all the passion required, Purgatory dramatises a failed attempt to bring this painful cycle of re-enactment to an end. There's no scenery save for a bare tree and a window representing a ruined mansion. The Old Man (Colm O'Neill), who brings his son (Charles Armstrong) to this spot, is the product of a disastrous passion between the heiress to the estate and a degenerate groom.
As the window of the house lights up, it becomes clear that the long dead woman is still in a purgatorial loop of having to relive her wedding night - on which fatal occasion the Old Man was conceived and a chain leading to the burning down of the house and to parricide was begun. A sickened witness now to his own begetting, the Old Man yearns for his mother's release which can only be achieved by remorse. But how can she experience that if each reliving depends upon her re-awakened sexual desires for the groom? In bitter desperation at this tragic twist, the Old Man tries to end the nightmare by knifing to death its ultimate consequence: his own son. For a moment, there's the cathartic illusion of peace: then the ordeal begins anew.
The play communicates a horrible, existentially vertiginous vision with mesmeric power and economy. It's joined here by Seamus Newham's spirited production of The Cat and the Moon, a Beckett-prefiguring piece where questions of faith are addressed in the comic knockabout between a blind man and a lame beggar who are seeking miracles at a holy well. In the deeply affecting tragedy of On Baile's Strand, the legendary Irish hero Cuchulain (Anthony Kernan) is manoeuvred by the wily King Conchubar into killing his own son for the stability of the state - a murky business of fly dependency outwitting nobler simplicity that is mocked in the framing story of a blind man cheating a fool of his dinner.
An alternative programme offers two plays (The Dreaming of the Bones and The Words upon the Window Pane) which, like Purgatory, confront the living with the ghosts of the past. Let's hope this season marks the start of a Yeats revival.
To 8 June. (0171-435 3648)