Hepburn! Walters! The re-rematch!

"I'm crazy about you, Katharine Hepburn," Barbara Walters says. "Call me Kate," Katharine Hepburn tells her. They don't just shower each other with rose petals, however, these two great American leading ladies. They get into some nitty and even a touch of gritty.

The interview, airing as the second segment on tonight's edition of ABC's "20/20," at 10 on Channel 7, and taped in Hepburn's quintessentially cozy Manhattan town house, marks the third time Hepburn has granted Walters an audience (or is it the other way around?). The occasion is the publication of "Me," a new Hepburn memoir. She's very cagey about how much she'll reveal and about making sure the interview plugs the book.

Hepburn is also one of the most intimidating humans on the planet -- Gorbachev or Bush or even Mike Tyson couldn't hold a candle to her -- but Walters is her inimitable unintimidatable self, pressing Hepburn to discuss her romance with the very married Spencer Tracy in more detail than she has before.

She does not seem to mind Walters calling the 27-year relationship an "affair" and even describes the night Tracy died at her home.

Discussing a much less meaningful fling -- this one with aviator, studio boss and world-class kook Howard Hughes -- Hepburn is typically, mischievously evasive. "Liked him very much. He was nice, and a very interesting man," she says. Apparently Hughes proposed but she turned him down. Walters doesn't ask Hepburn about Hughes's notorious zest for seducing starlets by the score on the RKO lot when the old lech was running it.

When Diane Sawyer interviewed Hepburn last season for "PrimeTime Live," Hepburn seemed upset at the mention of Hughes's name and breathed fire at Sawyer. Why the change? Because Hepburn felt it wasn't opportune to talk about it then. She was saving it. This canny grande dame knows how to sell a book.

She's also been interviewed by Katie Couric, the Great Cute Hope of NBC's "Today" show. Couric returns to that program, three-part Hepburn interview in hand, next week. And are they happy she's back.

Walters does not ask Hepburn what kind of tree, flower, bird, animal, vegetable or mineral she'd like to be. But she does ask her to complete the sentence, "Katharine Hepburn is ..." Hepburn offers two alternatives, a positive and a negative. No matter how often Barbara Walters visits her, Katharine Hepburn is determined to remain an enigma.

As tonight's interview demonstrates, there is little chance of her ever losing that status.

'Expose'

Reporter Brian Ross and his longtime producer, Ira Silverman, do the most formidable and impressive investigative reporting in television. Previously their work was showcased on "NBC Nightly News," but in recent months they've been consigned to the rather hopeless NBC News prime-time series "Expose," anchored by Tom Brokaw.

A Ross-Silverman piece will lead off the new season of "Expose" tonight as the series moves to a new time slot, Fridays at 8:30 on Channel 4. "Peaches" is not so much about that particular fruit as it is about a more forbidden one: crack cocaine, which pollutes not only America's urban areas but, as Ross and Silverman found out, even turns up in such seemingly incongruous locales as peach orchards.

Crack is "the ugly secret of the labor camps" where peaches are picked by poor migrant workers in Edgefield County, S.C., Ross says in tonight's scrupulously unnerving report. In attempting to uncover the sordid details, Ross and his crew are attacked on camera in one camp and threatened by two snarling peach growers.

An alleged crack dealer throws a bottle at the crew and cuts one of the technicians on the arm. We see the blood flow.

The piece tries to find a ray of hope in this squalor, one provided by a 70-year-old Irish Catholic nun named Sister Noreen, whose lifetime of good deeds includes hiding Jews from the Nazis during World War II. Now she tries to expose the conditions at the camps, which include the distribution of crack as a way of keeping the underpaid workers amused.

Ross never quite proves that crack is used to "recruit" migrant workers to come to the camps, and his claim that the situation amounts to "a new harvest of shame," a reference to the classic Ed Murrow documentary about migrant workers, is underdeveloped. The report seems too short; perhaps Ross and Silverman are overworked.

But what's on the screen is gripping and incriminating. Among those who come out looking foolish is Sen. Strom Thurmond (R-S.C.), who is seen railing against the scourge of crack on the floor of the Senate but refused to give Ross an interview for this report. Thurmond is twice glimpsed riding in a peach festival parade, appearing both oblivious and ridiculous.

Brian Ross is as imposing an investigative presence as Mike Wallace ever was on "60 Minutes," even though he's much more soft-spoken. He's the Eliot Ness of TV journalism, and it's kind of amazing that NBC News even keeps him on the payroll, since much of what that news division now produces has all the urgency and hard edge of slush.

It's unlikely "Expose" will succeed in its new Friday time slot, but if it's canceled, Ross and Silverman can go back to plying their dangerous trade on "Nightly News." In the report, Ross refers to Sister Noreen as "fearless." Coming from him, that's a supreme compliment.