HEADLONG

Tony Kushner's two-part, seven-hour epic, first seen in the early 1990s, certainly has its periodic longueurs. Yet its portrait of the crisis and confusion in Reagan's America is sustained by the daring of Kushner's concept and by a grand humanist vision that comes ringingly across in Daniel Kramer's fine revival for Headlong.

Kushner's subject is the American national psyche, and to explore this he focuses on two interlocking couples. Joe is a closeted Mormon Republican lawyer who eventually abandons his hallucinating wife, Harper. He then hooks up with Louis, a Jewish legal clerk who has guiltily deserted his lover, Prior, who is dying of an Aids-related illness. Behind them lurks the demonic figure of Roy Cohn, Senator McCarthy's former henchman, who discovers that political power offers no protection against terminal illness. And above them hovers an angel of death, who argues that a planet abandoned by God can only survive through stasis.

Although the angelic scenes in the second play, Perestroika, show Kushner at his most prolix, it is the rebuttal of the celestial credo that makes his concept so moving. On the personal level, he suggests there is liberation even in loss. And, on the public level, he argues for purposeful change. In the event, the myopic greed of Reagan's America may have been supplanted by the ideological fervour of Bush and the neo-cons. But Kushner's message about metamorphosis still holds good, and the final moments in which Prior, echoing Goethe's final words, cries, "More light!" are profoundly affecting.

Mixing fantasy and realism, soap-opera and grand opera, Kushner's twin plays present a daunting challenge to which Kramer and his eight-strong cast majestically rise. Greg Hicks's Cohn, arguing that he cannot be classified as gay since homosexuals have "zero clout", exudes the diabolical magnetism of Milton's Satan. In a classy ensemble there is also excellent work from Mark Emerson as Prior, Adam Levy as the conscience-torn Louis, Jo Stone-Fewings as the self-deceiving Mormon and Kirsty Bushell as his wife, prey to Valium-inspired visions. Obi Abili as a nursing drag-queen also raises one of the biggest laughs when he points out that The Star Spangled Banner "sets the word 'free' to a note so high no one can sing it". But that is characteristic of a play in which woe is always leavened by wit and which sends you out believing that even the most flawed political systems are still humanly perfectible.