Plays with only one actor pose problems for actors and theatre companies, and for audiences as well. They also afford some important opportunities and challenges. Because they're economical to put on -- and given the realities of theatre funding in recent years -- we've had lots of chances to consider such issues.

The Search for Signs of Intelligent Life in the Universe, Theatre New Brunswick's last production of this season, gives us another such opportunity. The play, as most people will know, was originally written for Lily Tomlin, who performed it on Broadway in the mid-eighties. Jane Wagner's script is a brilliant comedy routine, intelligent and neatly structured. It is, though, becoming somewhat dated; some of the American New Age fads it mocks feel almost as distant -- in space and time -- as the Victorian pretensions Oscar Wilde made fun of in The Importance of Being Earnest.

Michael Shamata chose it for TNB's last production, one imagines, not only because it would be relatively cheap, but also because it represents a kind of culmination of a season whose theme was an exploration of the roles of women and men. In fact, much of the last act of The Search feels like a sort of reprise of Yard Sale and If We Are Women, as a woman sells off the relics of her failed marriage -- and, perhaps, life -- in a giveaway yard sale, and ruminates over her situation.

Like The Importance of Being Earnest, but in a very different way, The Search is a challenging script. One problem is that for many of us who care about theatre, it's not really theatre when there's only one character. Lectures and standup comedy -- and sermons -- are about listening to someone talking to us: theatre, we think, is about observing groups of people interacting with each other. Another challenge, of course, is that the original Lily Tomlin production is one many people have seen, or seen parts of; it's important that a new production not be seen as simply a generic no-name imitation of the original.

Michael Shamata has addressed these problems with his usual skill and imagination. One strategy is to introduce what amounts almost to some extra characters -- the sound and light designers, Trevor Hughes and Luc Prairie. Unlike the original production, this one is rich in mime. Trudy, the bag lady who is the central character and our window into the lives of the others, has no bags of groceries, no umbrella hat, no piles of junk; she mimes jiggling her bags and unzipping valises, and although we don't see them, we hear the bags and the zipper. When those other characters pour invisible coffee or turn invisible pages in a book, Hughes's brilliant sound effects become almost a second character, whose role is nearly as visible as that of Tanja Jacobs, the actor we actually see as Trudy -- and as all the other characters of the play.

And as Trudy "dialswitches" into another character (under the malign influence, she explains, of too much time spent in electroshock therapy), the sound system zaps and snarls and broadcasts electrical angst; and at the same time Prairie's lights transform the stage from a street corner in New York ("At the corner of 'Walk' and 'Don't Walk'," Trudy explains) to a night club, to a geodesic dome house, to a New York taxicab. The technology comes to be an additional cast of characters, and in this production they play their roles with snap and precision.

Another strategy for dealing with the challenges posed by the show's size is to require the single actor to people the stage with a range of different characters, and especially with more than one at a time. Many of the most engaging scenes are those in which Jacobs takes two or three roles, moving back and forth between two speakers to give us a realized dramatic scene.

It remains, however, pretty difficult for a one-character play to fill a space as large as the playhouse: perhaps it takes a Lily Tomlin to carry it off. Tanja Jacobs is an amazingly accomplished actor, and we come to care about Trudy, and Marge, and Agnes, and a number of the other characters she plays. And we laugh regularly, and hard, at the brilliance of some of the play's more memorable lines. But finally, the show seems too small for the space, the characters not quite big enough, the stage not full enough of people and movement and characters and ideas.

One reason for this, it seemed on opening night, was that the pace seemed rushed, a little headlong. It needed, perhaps, more definition, more sense of having time to spare in the production. I don't mean that it should be slower, but rather that it might seem less hurried if there were clearer punctuation between the characters and scenes. Often, when Jacobs was doing two characters in dialogue, she seemed to be rushing to get into position to deliver a response, so much so that I sometimes lost track of which character was speaking. And at a number of points, lines were lost entirely in the rush, simply not projected to the back wall.

A slightly different difficulty involved the mime itself. Sometimes the space being "created" was not clear at all -- for instance, a number of scenes took place inside a geodesic dome home which included an "isolation tank." At various times the tank seemed to be in different places. In order for mime to work, the world it creates has to be as solid and permanent as a real one, for the mime and for the audience; when things move around we all tend to lose our focus.

In spite of these problems, the opening night audience enjoyed the show immensely; there were frequent local explosions of laughter in various parts of the house, at quite different things.

On balance, it's certainly worth going -- to see Tanja Jacobs' tour-de-force, to experience the technical legerdemain with which TNB frames the show, and to engage yourself with Jane Wagner's wit. But sit down front; the show needs some intimacy to work.