Caryl Churchill’s early masterpiece Cloud Nine was mind-blowing when it opened  in 1981 and it’s no less mind-blowing today, as revived at David Mamet’s off-Broadway Atlantic Theater Company in a delicious revival staged by James Macdonald. British playwright Churchill would go on to write more masterpieces — Mad Forest, Top Girls and Serious Money among them — but Cloud Nine exceeds our prayer that what seemed outrageous, fun, timely and, yes, game-changing 34 years ago, doesn’t make us wonder “What was I thinking?” today. Brilliant then, brilliant still.

Cloud NineAbove all, Cloud Nine remains the best play about sex, revolution and time travel ever written. OK, perhaps the only play about sex, revolution and time travel, but that’s beside the point. Men play women, girls play boys, gay becomes straight and straight, gay — and you might say that fluid, in several senses, rules. Act I is set in the twilight of the British empire, at a somewhere-in-Darkest-Africa outpost. The British governor (Clarke Thorell) dotes on his vacant wife (Chris Perfetti) and doll-loving son (Brooke Bloom) but is diddling the widow next door (Izzie Steele). When their manly friend Harry Bagley (John Sanders) arrives after his latest adventure, all the barriers fall as he pursues and is pursued by wife, son and the duplicitous servant (Sean Dugan) as the drumbeat of violent resistance grows in the near distance.

Act II takes place in London a century later, but the characters have aged only 25 years (stay with me; it’s easier done than said). Sexual freedom is the new revolutionary cause, relationships the disruptive minefield of social intercourse. The naïve mother has been sanded by time and self-discovery (and is now played by Brooke Bloom). The children (one formerly played by a much-abused doll) are struggling through their own entanglements, not without some emotional bruising. What was satire in Act I has aged, joltingly yet sympathetically, into pathos in Act II. Churchill’s razor-sharp comedy loses none of its bite even as her love for these messy characters in turbulent times struggle to find calm in a roiling sea of social upheaval. We have no problem riding the waves in part because we, too, have fallen a bit in love with them.

Cloud NineDesigner Dane Laffrey has made the Atlantic’s Linda Gross mainstage unrecognizable, dispensing with the standard configuration of the house and replacing it with bleacher seating that surrounds the action. I don’t get the benefit of that — seeing the play in the round adds nothing and the bleachers are terrifically uncomfortable. Never mind, though, for Macdonald has assembled a seamless ensemble and staged the show with a keen eye for its nuances, underplaying where no overstatement is needed. The crackle-golden lighting by Scott Zielinski and elegantly simple costumes by Gabriel Berry all conspire to make the evening as unforgettable as Tommy Tune’s original New York production all those many years ago. As a revelation, it’s déjà vu all over again.