If being mistaken for Judith Light is the worst thing that happens to Lisa Harrow in New York, then she's got it made. The day after she went into rehearsals for Wit, the actress attended the premiere of The Green Mile--sporting a freshly-shaven head. "People thought I was Judith, who had just been on The Rosie O'Donnell Show," says Harrow, who was "flattered" by the comparison. "Or they thought I was having chemotherapy, so they were very supportive. It's not a problem at all. It's something to do with the power of that woman, Vivian Bearing."

Harrow is now the third actress to experience firsthand the power of Wit's indomitable leading character, Dr. Vivian Bearing, the college professor whose struggle with ovarian cancer has won the hearts and sympathies of off-Broadway audiences--not to mention a heap of awards, including the 1999 Pulitzer Prize for Drama for playwright Margaret Edson. Harrow recently replaced Light, who departed to take Wit on a national tour. The original leading lady, Kathleen Chalfant, currently headlines a Los Angeles production at the Geffen Playhouse. Wit is going global--and not just with the casting of Harrow, a New Zealand-born, Royal Shakespeare Company-bred performer.

When Harrow first heard about the hit play she was in Vermont, where she has lived for two years with husband Roger Payne, one of the world's leading whale biologists. "I was in my kitchen, and I heard Kathleen talking about it on NPR," Harrow recalls. "I thought it sounded like the most fascinating play, and I'd love to have a go at that part." It's a formidable role, she concedes, "But then--not to boast--I've always played pretty formidable roles." (Eliza in Pygmalion, Viola in Twelfth Night, Anne Boleyn in Henry VIII, to name just a few.) "To be at the center of a play, driving the play, is not common for actresses. Yet it's what male leading actors experience all the time. So much writing for women doesn't really give them a chance to strut their stuff. I was completely stoked from the beginning."

After a couple of auditions--one with her own English accent, the second with the requisite American accent--Harrow was welcomed into what is known as "the Wit family". She and her predecessor discussed topics like sleep (Light told her to get a lot of it) and eyebrow bleaching, says Harrow. Playwright Edson "could not have been more helpful. I could talk to her about anything. I didn't feel I was doing anything but carrying on a tradition, taking something and making if my own." And the actress was fortunate enough to work a little with director Derek Anson Jones before he passed away. "I did my first day of rehearsal with him, then he came to a technical dress that we did and gave some extraordinary notes. We talked on the telephone several times," Harrow says. "I just wish I'd been able to have the whole three weeks with him. He was so tuned into language and clearly such an extraordinary intelligence. But I think Derek's work is in place."

And that work is appreciated again and again by audiences at the Union Square Theatre. "Every night you think, 'This is going to be a tricky one.' And they just go with you! They laugh and cry and at the end they give you a standing ovation. I think what they're responding to is the sheer humanity in this play. The journey that woman takes is such an extraordinary one. It's not an easy night in the theater, but it's a rewarding one."

There are some easy things about Wit--like the whole head-shaving business. "I did it the day after I started rehearsals," Harrow says. "My husband keeps telling me how beautiful I am. My son, who was at boarding school, arrived home with his head cropped almost to a shave in solidarity. And it's certainly an interesting way to save on shampoo."