On the face of it, it's not obvious that Alzheimer disease is a promising subject for a theatrical production -- especially not for a comedy. Even if one has known people to face the disease with courage and humor, and refuse to allow the insidious tangles in the brain to suck the humanity out of them without a fight, the finality of the diagnosis and the inexorable progress of the disease suggest that an evening in the theatre contemplating it would be the sort of thing that you might make an appointment for a root canal to avoid. Yes, we've all probably known someone who could find a way to laugh in the face of this horror, but we've also probably known people simply to sink into a black hole, to fade from human contact without hope, to be rendered a helpless stranger to the universe, from whom no light escapes; we've also known the burden that the disease imposes on the friends and family and loved ones around the patient as the lights, one by one, go off.

On the other hand, if you've experienced the dark, transforming humor in the face of despair of a Beckett or Swift or Brecht, you know that theatre is capable of making miracles out of despair -- without lying about the despair or faking the miracles. In a way, this is just about what the astonishing Dulcinea Langfelder and her colleagues have done with the production of a strange and wonderful entertainment called Victoria, which played one night at the Playhouse and which I'm very glad my skepticism didn't make me miss.

Victoria was created seven years ago by Langfelder and her company, and has been performed literally around the world, in seven different languages. I had never head of it (or of Langfelder's earlier creations), and I suspect this is partly because it's very difficult to know what to call it: it's more like theatre than anything else, but there are strong elements of dance, performance art, shadow show, and mime about it.

The play, if I can call it that, has two characters -- Victoria, an elderly woman who has been "warehoused," as it's often called, in some sort of hospital-like facility, where she apparently sometimes gets visitors (but of course does not know who they are: at a number of points in the show she addresses the audience: "How lovely of you to come and see me, even if I don't know who you are. If you hadn't come I'd never have recognized you"), and the orderly (played by the very impressive Patrick Florant) whom we watch caring for her, with exactly the sort of long-suffering, complaining but carrying on anyway patience that we imagine is the only way to survive such a job. Oh, and perhaps there's a third character, a brilliant coup de théâtre-- a shadow on the back of a curtain, Victoria but not Victoria, which is both her shadow and, in fact, a quite independent figure, as the audience is amazed to discover.

The action all takes place in an oddly exaggerated hospital-type room, with the tracked curtains doctors use to close off the patient's bed while private and awful things are done -- only in this cases the tracks make a ten-foot high serpentine around the stage, lit from the back and front as necessary, with Victoria in her wonderfully mobile wheelchair darting among and between them, and the sound of the tracks reminding us exactly of what it feel like in a hospital bed when a nurse or orderly pulls the curtain around you.

Langfelder, who plays Victoria, has a dancer's flexible and expressive body, and a wonderful doll-like innocence in her face under a shock of gray curls.  She makes us care instantly about this wonderfully resilient, ebullient lost soul, this person who has forgotten pretty much everybody and everything in the world, but remembers her cat and, in some strange way, who she is. She talks to us and to her orderly in a bright, disconnected and charming series of barely comprehensible monologues. At one point, liberating the tray with glasses of juice and little paper cups full of pills the orderly has left in her room, she wanders out into the audience, offering us drinks and explaining that the cups hold "little tiny cookies." At another, after we've heard the orderly complaining about the lack of diapers, she discovers that she's, um, soiled herself, and doesn't understand what the brown stuff all over her hands is ("a cacacacatastrophe," she says). Making the mess you'd expect, she wheels over to one of the curtains, making a mess of it, too, and eventually pulling it down over her head -- whereupon, of course, the orderly enters. "Holy shit," he mutters. "I don't have enough on my plate? You have to serve me this for dessert?"

Victoria, however, plays out, somewhere inside her tangled brain, a striking series of fantasies in which she dances (stealing the orderly's shoes, she even tapdances in her wheelchair).  She talks to her shadow on the curtain -- which turns out, through the magic of shadow projection, to be, perhaps, a shadow of who Victoria once was. She eventually participates in a lovely, wheelchair-bound pas de deux with the orderly, during which we realize, because of the sudden, astonishing blankness of her wonderfully animate face, that we've probably watched the last of her.

And yet somehow the experience leaves us not with a sense of loss and defeat, but of achievement and perhaps even triumph. After all, as Beckett and Swift and Brecht -- and the orderly -- tell us, we all die. As he's cleaning up, the orderly says, "the only reason we're keeping you alive is so that when you finally croak they can cut up your brain to find out why you were so crazy, and with a little luck, find a half decent organ or two." She responds, "You'll die?" "I'M not gonna die," he says, "YOU'RE gonna . . . " and doesn't finish. He knows, and we know.

And if we're lucky, we'll find a way to dance in our wheelchair on the way.