She thought she would never act again. "I'll tell you something fascinating," said Uta Hagen, looking fresh as a peony -- or maybe, thanks to those blue-blue eyes and her gentian-blue housecoat, a cornflower -- at an indecent hour in the morning. "I really thought that Mrs. Klein was my swan song."

Mrs. Klein was the play by Nicholas Wright about Melanie Klein, the psychoanalyst who in the 1930's had analyzed her own two young children, and paid for it, in which Hagen had triumphed last season.

"I was in it from the workshop to the Lortel and all through the tour, close to two years. When it closed, last December, I went into such a depression. Awful." Sitting there on the big battered couch in the big old apartment overlooking Washington Square, she put a hand on G.B. and shuddered. "I didn't want to do anything. I didn't want to teach," said one of the great acting teachers, not to mention one of the great actresses, of our time. "And I didn't teach, all that spring."

G. B. (for George Bernard Shaw, who else?) is a much-loved small brown poodle, and he isn't getting any younger either. The workshop was at the HB Studio -- founded by her husband Herbert Berghof in 1945 -- on Bank Street. The Lortel is the Lucille Lortel Theatre, where the Uta Hagen of Collected Stories, a new play by Donald Margulies, has now succeeded the Uta Hagen of Mrs. Klein.

Margulies -- as anyone who saw The Loman Family Picnic or Sight Unseen knows -- is a playwright who deals in serious subjects, often with scalding humor. "This play is not as strenuous as Mrs. Klein," she said, "but it's much funnier."

In it she plays a woman named Ruth -- "a teacher and prominent writer of novellas and short stories" -- whose life and work are appropriated by her student, Lisa (Lorca Simons), and recast to Lisa's own creative advantage.

"Remember the scandal a few years ago when the [now deceased] poet Stephen Spender had the most intimate details of his life put into a novel by some young man [David Leavitt] and sued and won? Well, Collected Stories is based on that premise. It's about betrayal -- something we've all experienced. It also has to do with the question: 'What does an artist have the right to do in terms of his own normal conscience?' What's most fascinating to me," she said, "is that at the end of the play, nobody's right." The person who was far more than right about both Mrs. Klein and Collected Stories was and is William Carden, once a student of hers, now the director of both plays as well as artistic director of the HB Playwrights Foundation.

"It's Billy who's responsible for everything. He got me Mrs. Klein, and it was Billy who called Margulies and said: 'Don't you have anything for Uta Hagen?' And Donald Margulies said: 'Well, there's this play of mine, Collected Stories, which was done at Manhattan Theatre Club . . .'

"I have a joke for you," said the woman I first beheld as a gorgeous Desdemona -- but no more gorgeous than now -- to Paul Robeson and Jose Ferrer 50 years ago. "I've always said I wanted to die onstage. Then when I was in Mrs. Klein I had bad, bad bronchitis, and took too much medication, and blanked out. Couldn't hear, couldn't see, couldn't breathe. I went to Billy Carden and said: 'I've changed my mind. I don't want to die onstage.' Billy said: 'Wait for the curtain call.' "

-- By Jerry Tallmer