Although Arena Stage has always strived to present the widest spectrum of theater possible, the experimental end of things has languished of late. The will was there, but the space wasn't. Call it a housing shortage.

A number of seasons back, the Old Vat Room took in plays in the making. But then funds ran out and a series of musical revues (which had the good grace not only to pay for themselves, but to show a profit as well) moved into the quarters.

For more than two years, in fact, Stephen Wade's "Banjo Dancing" has been playing in the Old Vat Room with no signs at all of wearing out its welcome. Splendid as that is for the ledger books, it has left unresolved--until now--the problem of where to put a thornier breed of works, the risk-taking plays that may not necessarily command a large audience, but deserve a hearing nonetheless.

Last night, Arena temporarily remedied the situation by opening a new playing space, its fourth in the complex. Carved out of a room that is alternately used for rehearsals and scenery construction, it has been dubbed The Scene Shop and seats about 150 spectators on padded chairs, one step up from folding. The stage is a simple platform, backed by black curtains, which is to say that it is functional.

What counts is that Arena has some vital elbow room for the time being. When The Scene Shop is not being claimed for rehearsals or scenery, it will be turned over to the exploration of plays that challenge and quite possibly frustrate an audience, uneasy plays that may well induce a state of uneasiness, plays that don't turn the other cheek or look politely the other way.

Much like, I should imagine, the inaugural offering, Emily Mann's "Still Life." Mann is examining an odd menage a trois born of the Vietnam war: Mark (Charles Janasz), a half-crazed veteran who discovered on the battlefield that he actually relished the power and taste of killing; Cheryl (Christina Moore), the puzzled wife he periodically beats up; and Nadine (Halo Wines), the 43-year-old other woman, who finds Mark "the greatest man I've ever known."

The three of them, seated at a long conference table, are recounting their personal histories--and often their versions of the same events--to the audience. Occasionally one character will acknowledge the other with a glance or a gesture, but for the most part, they are talking concurrently--the speeches of one overlapping, bisecting, undercutting the speeches of the others. Although not so austere or so formalized a work, "Still Life" manifests a certain kinship with Samuel Beckett's "Play."

In that work, three talking heads, imprisoned in funeral urns, attempted desperately to sort out the wreckage of their lives and force their fragmented memories into a coherent shape. Mann's characters are far more realistic creatures and their stories are, on the surface, perfectly comprehensible. But they are engaged in a similar activity. All of them have come up against the latent violence in the human beast. All are trying to understand it and, if understanding is not possible, at least learn how to put it on a short leash.

Because they are confronting a dilemma at least as old as Cain and Abel, they can handle it only indirectly. Mark's primary approach is to infect others with the awful images in his head (a photographer, he even has some grisly battlefield slides to show us). If he cannot explain why he acted the way he did, he can at least share the horror in his skull. And maybe sharing it is the first step toward defusing it.

Nadine is compassion itself, but since most of her understanding is lavished on Mark, with whom she is apparently having a deeply spiritual and physical affair, it can be considered at least partially suspect. Meanwhile, Cheryl defensively professes no exact recollection of events and merely wants to get on with the business of raising her kids.

Although all of them believe "the war is the basis of all our problems," the war has merely sensitized them to a part of their own nature. It is Nadine who gets to the crux of the evening when she observes, "The problem now is to figure out what to do with what we know." Mann has no more answers than her characters, and her play is decidedly open-ended. What she shows us are three psyches, grappling with the darkness within.

For anyone who demands tidy plays and a well-ordered universe, "Still Life" will be something of a 90-minute torment. While there is some humor, provided chiefly by the ironic juxtaposition of speeches, this is essentially a play built out of question marks. It does not ask to be liked, but it does expect to be listened to. In that sense, however, the unspoken words behind the characters' monologues can often be tantalizing. When Cheryl, for instance, tells us about the traumas she suffers each time her husband prepares his once-a-year spaghetti dinner for 40, she is clearly detailing frustrations of a far greater magnitude.

Since the three cast members are extraordinarily convincing in their bewilderment and their anguish, "Still Life" will lay claim to your attention. It is even likely to set a few wheels spinning. Certainly no one else is doing this sort of play in Washington at the moment and this sort of play definitely should be done.

The Scene Shop will allow Arena to multiply its fare. It will allow the rest of us to expand our dramatic horizons.

STILL LIFE. By Emily Mann. Directed by James Nicola. With Charles Janasz, Christina Moore, Halo Wines. Costumes, Marjorie Slaiman; lighting, Nancy Schertler. At Arena's Scene Shop through June 19.