With Meryl Streep and William Hurt in the cast, it's easy to conclude that "One True Thing" is bound to be an emotionally charged drama and that it's probably a good idea to bring Kleenex. Good plan.

Streep plays Kate Gulden, the cancer-stricken, proud, pre-feminist homemaker of a New England family who perseveres through her illness with a halcyon happy face, continuing to make sure all her ducks are in a row, even while her health deteriorates.

Hurt is her husband George, a respected and adored literature professor who is full of all-too-honest opinions and 50-cent words. Somewhat in denial of his wife's illness, he carries on with his life as normal after guilt-tripping their daughter into abandoning her budding journalism career at the New Yorker to move home and care for her ailing mom.

The daughter, Ellen (played by Renee Zellweger, the mellow, incandescent actress who nearly stole "Jerry Maguire" from Tom Cruise), is the heart of the film. Focusing on her often tenuous relationship with her mother, the story -- adapted from the novel by Anna Quindlen -- is of the family's emotional endurance as Ellen struggles with having been thrown back in with her over-bearing parents while they all subconsciously prepare for the mother's inevitable death.

Directed by Carl Franklin ("Devil in a Blue Dress") with an eye for the light moments as well as the grief, "One True Thing" has the most honest, layered and authentic family dynamic of any American movie in recent memory. (Although with such a cast, who could be surprised?)

As it invites the audience inside the Gulden household, everything rings true: Self-sacrificing Kate's motherly mannerisms -- at once tender, loving and manipulative. The comfortable routine of Hurt and Streep's husband and wife yoke that is upset by Kate's declining health. The power struggle in the mother-daughter relationship, and the effect Ellen's career interruption has on their interaction as she cares for her mother, inspiring resentment, compassion and a mutual appreciation between these two women that didn't previously exist.

But most of Ellen's resentment is reserved for her father. She recognizes from him a modicum of disrespect, for instance in the way he critiques her writing, which accentuates his insistence that she be the one to give up her livelihood for her mother.

Bonded by their passion for writing, the father-daughter covenant becomes strained over this, and builds toward an eruption as he continues to take on a full class load and selfishly disappears in the evenings to what his daughter suspects are sexual liaisons.

All of this tension is magnified by the fact that the family knows they are working out their differences against an unspoken deadline.

The film is narrated by Zellweger as she relates the months leading to her mother's passing to a district attorney, the reasons for which are not made immediately clear, and this mystery burdens the storytelling severely in spots.

Haunted superficially by other scattered imperfections -- like the fact that Zellweger's character is described as cold and ambitious when she clearly is not -- the film is nonetheless a perceptive, true-to-life reflection of family pathos, due to astute performances from perfectly cast actors.

Hurt, who has made a career of creating these types of understated yet emotionally boundless characters, turns in one of his most subtle and at the same time most raw performances as a devoted yet distant husband hiding his fear of loneliness.

Zellweger holds her own against two powerful stars with all the strength of a industrious writer and the vulnerability of an adult daughter still intimidated by her parents.

And after spending these two hours watching Streep slowly slip away into the ethers in what may be her warmest, most vulernably human performance to date, I wanted to go straight home to call my mother and tell her I love her.

Indirectly reminiscent of Mike Leigh's "Secrets and Lies" in its familial authenticity (although it's not nearly as naked emotionally), "One True Thing" is sometimes a little too obvious and convenient (gee, I wonder who will finish the porcelain mosaic Kate works on throughout the picture...), but it is as affecting and sincere as a studio picture could ever be.