Although the dates of those plays might suggest that Shawn is due for a work that might extend his unsettling trilogy to a tetralogy, he's announced no new piece but is instead being implicitly acknowledged as something of a visionary in New Group artistic director Scott Elliott's crisp, ominous revival of Aunt Dan and Lemon. The grim truth of Elliott's treatment -- for which Shawn has apparently done few or no rewrites, other than a droll, prefatory turn-off-your-cell-phones warning -- is that the play's message about casual global acceptance of violence seems even more relevant in 2003 than it was to what now feel like the infinitely more halcyon days of 1985.

The eponymous Lemon (Lili Taylor, wearing a Les Miz T-shirt and a sporty ponytail) narrates Shawn's play. Refreshing as the lime and celery juice that she drinks because she has trouble digesting solid food, Lemon gladly indulges herself in a capsule autobiography, devoting the largest part of her account to Aunt Dan (Kristen Johnston, who gives as good a performance as you'll find on a local stage these weeks). Because Lemon's father (Bill Sage) and mother (Melissa Errico) are too caught up in marital discord to tend to her, she turns for guidance through her impressionable early adolescent years to family-friend-called-aunt Dan.

A jovial mentor with a fascistic turn of mind, Dan has the sway over Lemon that favorite relatives often do. So if Lemon's mother listens quietly shocked through Dan's hearty political diatribes, Lemon absorbs certain damaging influences. For instance, in defending Henry Kissinger's decision to bomb Cambodia, Dan orates: "Look at that face! He can stay up night after night having a wonderful time with beautiful girls but he will always have that look on his face, my Lemon, that look of melancholy, because he has seen the power of evil in the world."

In addition of airing her beliefs and judgments, Dan regales Lemon with stories of the various jet-setters of her acquaintance who live the decadent life that, with Paris Hilton garnering so much column space recently, doesn't seem to have gone out of style. In particular, she tells -- and she and Lemon watch played out as if they're voyeurs on the set of a snuff film -- a tale of Mindy (Brooke Sunny Moriber), an arachnid of a woman who lures powerful men to her apartment and has her wicked way with them. One of the play's most disturbing scenes is Mindy's make-out-then-do-in session with a slick but ultimately gulled South American Lothario (Carlos Leon).

Aunt Dan could be Auntie Maim in an inside-out version of Patrick Dennis's famous valentine to his fave-rave relative. The manner in which Dan has washed Lemon's brain with soft soap leads to Shawn's final peroration -- one wherein the poor protagonist, a satisfied recluse, explains at some length her tempered admiration for Nazism. "It's easy to say we should all be loving and sweet," she chirps as if giving a morale-boosting lecture, "but meanwhile we're enjoying a certain way of life -- and we're actually living -- due to the existence of certain other people who are willing to take the job of killing on their own backs, and it's not a bad thing every once in a while to admit that that's the way we're living, and even to give to those certain people a tiny, fractional crumb of thanks."

That speech, delivered in the closing moments of Aunt Dan and Lemon, is horrifying and devastating. It's also a speech that some observers took to be Shawn's perspective when the play debuted, although it quite obviously isn't; rather, it's his hard look at moral turpitude. As such, what Shawn says through Lemon's unshakable convictions is the obverse of his message about the weak-willed men depicted in The Fever and The Designated Mourner -- men disoriented by the collapsing social structures in which they live and are disinclined to ameliorate. This is the way civilizations crumble, Shawn intuits and sets forth.

Director Elliott gives Shawn's piece every bit of help he can with, first of all, his deployment of the cast. Kristen Johnston's homey defense of Kissinger is one of the high points of the current season. The temptation is mighty to think about this actress's long run on television's Third Rock From the Sun (two Emmy awards there) and suddenly see all of the performing she did thereon as warming up for this chilling role. As she sits bosomy and fleshy in a low-cut dress (Eric Becker's costumes), she exudes the appeal of a girl who's everybody's best friend. Lili Taylor, already beaming away as the audience enters, may not have the most convincing English accent around but she slides into Lemon with the takeover ease she brings to everything she does. (That Les Miz T-shirt is another canny Becker touch since it speaks of misery and suggests that Taylor is carrying Lemon's inner child on the outside.)

The remainder of the cast -- most notably Melissa Errico and Moriber -- lend creepy verisimilitude to Shawn's take on decadence. This Aunt Dan and Lemon takes place, courtesy of designer Derek McLane, in front of ceiling-high, wine-red scalloped draperies; a couple of chairs, a bed, and a dining table are the only furnishings. Jason Lyons lights the areas properly, and the equally fitting sound design is by Ken Travis.

Since we appear to be living in increasingly parlous times, Wallace Shawn's 18-year-old drama seems all the more important to scrutinizing the make-up of the parlousness. After all, when a country is run by a man who sometimes seems to have his own favorite Aunt and Uncle Dans, it's helpful to have on hand a playwright who's noticed and who can trot out an 18-year-old work that has something to say about the situation.