The first thing to know about "An Angel at My Table" is that this two-hour, 40-minute movie isn't a movie at all — it's a New Zealand TV miniseries whose three parts have been tied together.

Fans of PBS know that languorous pacing in stories with little action or humor is fine for one-hour installments taken over several evenings. But the result of running them together as a movie can be rather stultifying.

That rule isn't necessarily broken here, but there is so much richness, primarily in the treatment of the central character, that the patient viewer will be rewarded.

Based on three autobiographical novels by Janet Frame, a celebrated New Zealand novelist and short-story writer, "An Angel at My Table" is essentially three movies exploring three different periods of the author's life.

The first section, "To the Is-Land," far and away the most satisfying for me, observes Frame as an unhappy, overweight little girl growing up in poverty during the Depression. While her large family is rowdy and uncouth, it is also intellectually stimulating, and during this time she discovers the joy of books. But she also grows more introverted and awkward, embarrassed by her shock of red hair, her inability to make or keep friends and discouragement from her teachers.

The second section, "An Angel at My Table," follows Frame to college, where she is still unable to fit in with her peers. She eventually earns her degree and becomes a teacher, only to freeze at the chalkboard the minute an adult enters the room to observe her. It isn't long before she is diagnosed — wrongly — as schizophrenic, finds herself hospitalized and undergoes continual shock treatments. It is her writing talent that literally helps her to escape before a lobotomy is performed. Unfortunately, much of this section has a "Snake Pit" quality to it, which never allows it to become distinguished from other mental institution horror films.

Better is "The Envoy from Mirror City," a lighter segment that has Frame traveling Europe on a literary fellowship, stumbling onto the bohemian art world of the '50s and having her first, albeit awkward, romantic relationship . . . with an obnoxious American teacher who fancies himself a poet. By this time, though she is still uncomfortable in social situations, Frame seems to have gained enough confidence to learn from the experience rather than let it completely devastate her.

What is perhaps most striking about "An Angel at My Table" to anyone who has seen director Jane Campion's "Sweetie," is that it is so straight-forward in its storytelling. I found "Sweetie" extremely self-indulgent, filled with odd camera tricks that didn't seem to service the story. "Angel," however, is quite the opposite, never allowing the camera to become intrusive, even as it slowly takes in the landscape as part of the story.

The screenplay, by Australian Laura Jones, is remarkably intimate, filled with fine details and anecdotes. And the performances are uniformly excellent, with special kudos to the three who play Frame at different ages — Alexia Keogh as young Janet, Karen Fergusson as teenage Janet and Kerry Fox as the adult Janet. Each is called upon to portray different stages of a very brittle character, whose inner pain is evident but subtle. And each does an admirable job.

"An Angel at My Table" is rated R for sex, nudity, profanity and vulgarity.