Busy is not the word for playwright and performer Rinne Groff. Her play Inky just opened at Altered Stages, she is about to leave on a national tour with Elevator Repair Service, the performance group she co-founded, and in April, Target Margin Theater will produce her newest play, The Five Hysterical Girls Theorem. Not bad for someone who just finished graduate school in May.

Groff, a charming and eloquent Florida native fresh out of the graduate dramatic writing program at NYU, is no stranger to Off-Off Broadway. She moved to New York after she graduated from Yale in 1991 to pursue a career as an actress. Shortly afterwards, she began collaborating with John Collins and some other Yale alums, and Elevator Repair Service was born.

ERS, as they are commonly known, use text, movement and sound in a completely original way to explore everything from documentary filmmaking to Andy Kaufman. With titles like Marx Brothers on Horseback Salad, Spine Check, Shut Up I Tell You, and their latest touring production, Total Fictional Lie, ERS's particular brand of absurdist humor has made them unlikely critical darlings. They regularly have sold-out performances in downtown New York venues and have traveled to festivals in Germany, Austria, Amsterdam, Switzerland, and most recently, Slovenia. Groff seems somewhat amazed by the group's success. "I remember I sat next to John Collins at graduation and we started talking about how we were both moving to New York and that we should get together and work on something," she recalls. "I never dreamt it would become this big thing. I just find the work we do so satisfying."

The more traditional world of acting proved less satisfying to Groff. She paid her dues and did some regional theater work, but no longer found acting as fulfilling as it had been to her. After a little soul searching and two months in India studying yoga, she decided she wanted to write plays. She applied to graduate school because she felt like she needed structure, explaining, "In the past I started things, but never finished them. I knew graduate school would force me to finish things."

And finish things she did. Theatergoers can see some of the fruits of Groff's labors at Altered Stages through February 12. Clubbed Thumb, an up-and-coming theater company and a co-producer of the much-touted Mac Wellman festival, is producing Inky, the weird and moving tale of a nanny (named Inky), of unknown Eastern European descent, who brings her love of Mohammed Ali and boxing to an unsuspecting yuppie family. Nothing is the same after Inky's arrival, when members of the family find themselves fighting in new and unsuspected ways.

Maria Striar, one of the artistic directors of Clubbed Thumb and the star of Inky, was drawn to the play's intelligence. "We like to produce plays that never underestimate how smart our audience is," Striar explained. "We look for plays that are bright and brave and that have a certain humor. Inky is all of those things. It really leapt off the page."

Striar leaps off the stage in her inspired performance as Inky. Groff's quirky writing and Striar's disciplined and meticulous performance create a remarkable and unpredictable character.

The inspiration for Inky comes from an unlikely source--the actual words of the prize fighter Mohammed Ali. Groff was given a book containing interviews with Ali, and found that "the way he used words was amazing. I'm really interested as a writer in the times people speak in poetic ways," says Groff. "I like exploring what brings out non-pedestrian language in someone." There is certainly nothing pedestrian about the language in Inky. The play crackles and pops and, in the words of Ali himself, "floats like a butterfly and stings like a bee."

Language is also at the center of Groff's next play, The Five Hysterical Girls Theorem, which was commissioned by David Herskovits for Target Margin Theater and will open April 19 at the Connelly Center. Target Margin, an Obie Award-winning theater group, is best known for its re-interpretations of Shakespeare and popular and forgotten classics, but is devoting its 1999-2000 season to new plays. In choosing the plays he wanted to produce Herskovits looked for "texts that stretch beyond the familiar, that seek to incarnate imaginary worlds, that will spark the mind and free the spirit."

Groff's next play sounds like it just might do all that. The Five Hysterical Girls Theorem is set in 1913 and is about a famous mathematician who travels with his family to a seaside resort, where a startling revelation is about to be presented to an illustrious group of number theorists. In the last few years Groff has become more and more interested in mathematicians and scientists. "I'm very intrigued by the way mathematicians speak about their work. They talk about writing a beautiful proof, a concise proof, an elegant proof. For some reason I find that very moving."

And how does it feel to be performing on tour while her plays are being performed in New York? "Lucky. I feel lucky that I have had these long and fruitful relationships with a lot of really talented people," says Groff, "and that they continue to take an interest in my work."