SAN FRANCISCO, JUNE 4 -- "The mystery of the missing Raisa Gorbachev has been solved," said the radio announcer early this afternoon.

"It appears that she wanted to see the Twin Peaks," he explained breathlessly. Not the television show -- she wanted to see the best view of the Bay Area from this spot near two radio towers at the top of a hill.

She also wanted to see a mom and pop grocery store -- where she checked out the prices of vodka and declared Stolichnaya the better buy.

But in the process, the Soviet First Lady left staff, reporters, American protocol officials and most of the Bay Area guessing about her plans for the day. And that seemed to suit her just fine.

Her official day began at 10:15 a.m., with an hour-long visit with former First Lady Nancy Reagan, who at past meetings was reportedly chilly toward her Soviet counterpart. While former president Ronald Reagan and Soviet leader Mikhail Gorbachev talked over coffee at the Soviet consul general's Pacific Heights mansion, the two women sat catty-corner from each other, smiling and chatting. When the Reagans left, Nancy Reagan and Raisa Gorbachev shook hands.

"It was very nice," Nancy Reagan said later. "I think there's been a great misunderstanding about our relationship. We get along fine."

As for the earlier meetings between the two, she said, "It was a very different time. We were plowing new ground."

Reagan's spokesman Mark Weinberg said that "during their conversation, Mrs. Gorbachev mentioned press accounts suggesting she and Mrs. Reagan did not get along. Mrs. Gorbachev told Mrs. Reagan she regretted these reports because they were not true.

"Mrs. Reagan told Mrs. Gorbachev that she, too, was disturbed by such reports because she also knew they were not true," Weinberg said.

The former president's office also announced that the Reagans had accepted the Gorbachevs' invitation to visit the Soviet Union in September.

For all the talk about how quiet and subdued Mrs. Gorbachev has been on this trip, today she reminded anybody who needed it that she is still a very independent woman.

At Stanford University, where she arrived with her husband for his speech to students and faculty, Raisa Gorbachev worked the crowd on her own -- leaving her husband's side to ask for a banner that said "I love Gorby" in Russian.

At one point, she invited a 6-year-old boy from beyond the ropes to walk with her and pose for pictures. And when six artists presented their works for her perusal, she offered very confident and unwavering interpretations of their work.

"This is a warning to us?" she asked one artist of his dark, ominous-looking creation.

"A blessing," he replied.

"I see, there is a coincidence here," she said. "Now is also the era for us to recall the apocalypse, because of the things that man often does to man. There is a constant struggle between good and evil," she said as the artist, Richard Payne, looked so moved by the analysis that he was close to tears.

"So," she added, smiling with the assurance of someone who knew she had surprised her audience. "I understood you."

For another artist, whose painting was a swirl of colors, Mrs. Gorbachev saw "all human feelings, a face that is being driven all over the world."

After she moved on, the artist, Cynthia Schuman, was distraught.

"What she said was so moving and deep and we don't even have it on tape," she moaned, acknowledging later that she could not remember exactly what the First Lady had said.

While Gorbachev gave his speech at Stanford, Mrs. Gorbachev "just took off" from the campus, Carri Cummings, spokeswoman for a public relations firm helping to coordinate the Gorbachev visit, told Associated Press.

There was some confusion over just what Mrs. Gorbachev did, said Juanita Sullivan, another spokeswoman for the firm, the PBN Corp. The Secret Service "was kind of in the dark too," she said.

From Stanford, Mrs. Gorbachev was to have gone on a minutely scheduled hour-long tourist swing through the city, including a stop at the Bank of America's towering corporate headquarters, where Sherry Agnos, wife of Mayor Art Agnos, and bank executives were to meet with her.

Instead she took off for Twin Peaks and Fisherman's Wharf, where she continued the research on American markets that she began during her Minneapolis stop the day before.

She then went by the Palace of Fine Arts and the earthquake-damaged Marina district, before returning to the consul general's residence for a scheduled meeting with the Friends of Raisa, a group of women who have met Mrs. Gorbachev on their trips to the Soviet Union to promote peace.

Late in the day, Mrs. Gorbachev joined her husband for an impromptu press conference outside the consul general's residence, where the Soviet first couple stayed.

In response to a question about how she had enjoyed her spontaneous tour, Mrs. Gorbachev said she had toured Chinatown and Russian Hill, and that a cable car driver had mentioned to her that "he had a friend who would do Mrs. Gorbachev's hairstyle for free -- so I thanked him."

"Overall, I'd say that I'm overwhelmed by this beautiful city," Mrs. Gorbachev said, "so I wish peace and happiness to all the people of San Francisco."

Staff writer Cynthia Gorney and wire services contributed to this report.