Offering a climax to the celebration of playwrights at the NotaBle Acts Festival, Len Falkenstein's Free / Fall is an ambitious, complex and challenging play. It weaves wildly disparate themes and ideas into a tapestry (or sometimes collage) of images and sounds that remains tantalizingly in the memory well after the lights have gone down. Leaving the connections largely up to the audience to make for themselves, the company Falkenstein has put together shifts us abruptly from a series of backslide image-illustrated monologues about Romanian history, the fall of the Soviet Union, vampires, 9/11, and people's lives into a jagged narrative of two apparently quite different and obviously quite separate couples, one in Canada and one in Romania, whose lives intersect and parallel in a kaleidoscope of patterns. "Don't talk to me about coincidence," one character shouts. "Coincidence is a convenient fiction."

According to the Festival Web site, Free / Fall is "a play about falling walls, closed borders, shifting frontiers of the mind, and vampires." That seems as close to a description of its focus as we're likely to get. Falkenstein himself calls it, in his notes, "a response to . . . a particularly unsettled and anxious time in our collective history." And certainly anxiety -- ripening regularly into fear -- is one motif that recurs pretty regularly. So is a mordant and occasionally hilarious comic sense.

Opening on a bare stage, backed by three screens on which are projected a rich, various, and astonishingly well-timed series of images, maps, titles, photographs, the play entails four actors (and a tiny but crucial part for "a girl," played by Hilary Ball) using a minimal range of props, and an electronically-enhanced violin off in the stage-right shadows, punctuating and supporting the action in ways that will be familiar to those who know Falkenstein's other work. Performed by Jennifer Roberge-Renaud, it provides not only mood music, but sound effects and screeches, squawks and howls which heighten tension and make sure we all know everything's intentional and everything means something.

The four young actors who perform this play (and who have been -- and presumably will continue -- workshopping the play with Falkenstein) do an astonishing, energetic, disciplined job of keeping the audience engaged, of making us watch what's happening right now even though we have, at the moment, no idea whatever what its connection might be with what's gone before. As I've said before, Falkenstein's work reminds me of Caryl Churchill or Charles Mee in its disregard for conventional ideas of coherence and order. One of the challenges of a play in this tradition is that if the scene or event right in front of us isn't powerful and compelling on its own, we might drift away from the attempt to hold everything together and allow it to become one damn thing after another. Live theatre has immense power to engage an audience and keep it attending -- these are real people here, they care about what they're doing, we can't press the stop button and go get a beer -- and plays like this test it to its limits.

All four actors are familiar faces. Terry McKinnon (most relevant here is her touching and vulnerable Grusha in last year's Caucasian Chalk Circle at Theatre Saint Thomas), plays Justina, a Canadian who develops the compelling urge to go to Romania and adopt an orphan of the revolution. Josef Addleman, who is particularly experienced in working with Falkenstein (as, for instance, as Ambrose in Happy City, Banquo in Macbeth, and Tom in Manifesto) is Joe, her companion on the trip, and in other ways. Joe is identified as an International Relations Consultant, who turns out to have failing kidneys, a "top secret" job, and a desire to go to Romania as well.

In their many monologues addressed to the audience (or to some suspended interior interlocutor) and particularly in their conversations with each other, McKinnon and (perhaps especially) Addleman engage us in their motives and aspirations and fears, even when we don't entirely understand them. Besides the tight precision of their conversation, I was particularly impressed with McKinnon's athletic ability to look like a rag doll being tossed about by an alien tractor beam to be inspected, and ultimately refused, for abduction (well, I said the play incorporates disparate elements). Addleman, as usual, makes the strangest language sound authentic and reasonable, and has remarkable physical stage presence -- whether interviewing a vampire over bloody marys in his underwear ("I have just one question," he says. Is this really happening?") or stepping into an overhead spot to explain his motives.

Matthew Spinney plays Constantin, the descendant of Vlad the Impaler, the Romanian folk hero/despot who is, in a vague and roundabout way, the inspiration of Bram Stoker's and the movies' version of Dracula. Spinney was, among other things, Macbeth, and Mehmet in Happy City; here he takes on a challenging role, as both the place-bound Romanian facing the issue of an international proposal to build a Dracula Theme Park on his front door and the dreamlike Bela Lugosi-style vampire with the elegant central European accent and the cape. His narrative of his attempt to smuggle himself to Canada and his strange death -- which yields the title of the play -- is one of the most memorable speeches of a play rich in memorable speeches.

His relationship -- which we see as increasingly parallel, often presented as cross-cut interpolated scenes from opposite sides of the stage -- is with the obsessive and powerfully attractive Natalia (Marissa Robinson), who dreams of trips on the train to Budapest, and who, raped during the "celebrations" around the fall of the Ceaucescu regime, dreams of finding the child she gave up at the time. Robinson is also a veteran of Falkenstein productions (among others, Celeste in Happy City and Jenny in last year's The Donnellys). She is magnetic and powerful here, particularly in the completely convincing conversations with Constantin, in the remarkably athletic and affecting dream-sequence knife fight with Justina over the child, and in the spotlit monologues where all she has is the language -- which, as usual, she inhabits fully.

If the play is rather too long, and includes more than we think we need, it's difficult to imagine what might be cut without significant loss: though the opening sequence of monologues goes on too long (it's at least ten minutes into the production before the first words are exchanged between characters) it's difficult to think of what we might sacrifice in the exposition; similarly, one might argue that the parallel scenes between the lovers in a long sequence back-titled "Couplings" goes on too long, and yet the hinted and explicit parallels are important to our later understanding of the complex relations among the four of them. Falkenstein says in his notes that he appreciates the chance to work "on a larger canvas," and certainly the production is remarkably effective, from the impeccably timed back projections to Mike Johnston and Greg Shanks' similarly precise lighting (including moving strobe spots for the "alien abduction") to the perfectly pitched soundscape. As always with his scripts, in spite of the rich theatrical imagination (due in part to the collaboration with Johnston) and the visual and aural elaboration, though, it's all mainly about language; it's about the way ideas split, fuse, spin off implications and allusions and images which come back transformed later, and thus keep us attending and wondering. The cast manages, for the most part, to give us that language whole.

Like most of the other productions in this year's remarkably successful Summer Theatre Festival, this is a work in progress. Like them, it tiptoes along the line between workshop and the sacred space of theatre, where nothing's an accident and everything's significant, and like them, it leaves an audience hoping that those involved continue working on it and helping it grow, wondering what strange flowers might bloom between now and next time we have a chance to see it (which, I'm told, will be next October in the Black Box). I can hardly wait.