Actor and writer David Marshall Grant's new play Pen at the Guthrie's Dowling Studio begins like a highbrow family sitcom; it's witty, toxic and familiar. But sit tight. By intermission, the play leaps into wonder and insight. What had been entertaining, if derivative, transforms into riveting theater.

It's 1969. Seventeen and college-bound, young Matt teeters on the fulcrum of an unstable triangle. His hyper-controlling New York mother, Helen, is determined that he should go to college nearby. Multiple sclerosis has rendered her legs useless and confined her to a wheelchair, making her demanding and dependent. Matt, who is an impulsive shoplifter, has secretly applied for early admission to his father's alma mater in far away California. His father, Jerry, urges him to go, to get away. Jerry has escaped by divorcing Helen, finding a younger woman and leaving Matt to cope at home in a tumble of anger, love, guilt and resentment.

Bob Melrose directs Pen and his casting is spot-on, so that the three characters feel like flesh and blood people. Marc Halsey wears sensitive and callow Matt like a second skin, and looks 17. Helen, played by attractive Michelle Barber, fires off her character's acid tongue as though it were her own. She flings out Helen's Jewish hatred of all things German, her liberal fervor and her likeable sense of humor with easy flair. Marc Callen plays Jerry, a good-looking but insensitive psychologist. Jerry is self-absorbed and has yet to confront his own issues of guilt, even as he embraces his new freedom.

This black box theater production is not lavish as are so many Guthrie plays. Rather, it focuses on strong acting with Marshall Grant's engaging script, where sharp dialogue defines character. In Rob Melrose's design, a plain backdrop is lit from behind in luminous color, and simple period props make up the set. The play needs no more; it carries itself on powerful acting and a sound script.

Grant sprinkles the play with metaphors, the most powerful being a red zero-gravity pen, developed for use in space, in which the ink will flow regardless of the position and exterior circumstances of the pen. The pen gives Helen the power to write while lying down. Matt steals her pen. When he returns it to her, he conjures into being a dramatic shift in circumstance.

Costumer Christina A. Richardson dresses Helen in a natty little red dress and matching coat, and in unfortunate '60s-do wigs; but that was the stiff, beehive look of the time, I suppose. I appreciated C. Andrew Mayer's cool saxophone jazz sound design and Melrose's details of directing, like Matt switching on his parents with a television remote control.

Whether you perceive what happens in Pen to be dream, fantasy or magic realism, it is very good theater.

Pen, November 7 - 27, 2007. Wednesdays - Saturdays 7:30 p.m., Sundays 7:00 p.m. Matinee Saturday, November 17 1: 00 p.m.. Tickets $18 - $34. 612- 377-2224 or toll free 877-44-STAGE. Guthrie Theater, 818, South 2nd Street, Minneapolis, MN. 55414. www.guthrietheater.org.

- Elizabeth Weir