A Platonic dialogue in the form of a double anachronism--the action takes place two centuries after our era--Joseph Brodsky's only play, "Marbles," is set in a prison cell that alone provides for the three unities of classic drama: those of time, place, and action. A nightmare rather than a utopia, this play proceeds according to the immanent logic of mental aggravation as its two characters, the inmates Publius and Tullius, examine the tautology of their psychological, historical, and purely physical confines. The fusion of its dour, somewhat terrifying vision with the macabre hilarity of its verbal texture allows Marbles to take its audience beyond the farthest reaches of the theatre of the absurd, into territory more suitable for modernist imagination than for human experience.