The is seen only fleetingly, hurrying in and out of a Madrid apartment building in dark glasses and heavy fur coats and losing herself in crowds of armed guards.

She has not spoken publicly in almost seven years, and her only reported comments filter through bodyguards or former associates who may or may not have talked with her. She is said to want to visit the family of the late Panamanian leader, Omar Torrijos. It is said that she will soon vacation on the Mediterranean or that she will have an audience with Pope John Paul II.

Or, to the quiet distraction of many of this country's struggling political leaders, it is said that Maria Estela Martinez de Peron--Isabel Peron, the last constitutional president of Argentina--would like to come home.

On March 24, the anniversary of the 1976 military coup that ended her 21-month government, Peron will be legally able to return to Argentina from exile in Spain. She remains banned by both military decree and criminal court sentence from acting in politics, and she has not offered the slightest indication of what she plans to do.

Nevertheless, in a country where politics easily blend with intrigue and the bizarre, Isabel Peron, the 52-year-old former nightclub dancer who conducted one of Argentina's most disastrous modern governments, is viewed as the most potent wild card in the country's next venture in democracy.

Her allure only begins with her status as an exiled former president. Peron also bears a legacy as the third and last wife of the late Juan Domingo Peron, the leader who shaped much of modern Argentine politics. As his successor in a traditionally autocratic movement, Isabel Peron could exert a major influence on the future of the surviving Peronist party.

Although now divided by a struggle over their party's structure and leadership, the Peronists are still considered the dominant national political movement by many Argentine analysts. If her most loyal followers have their way, Peron could swing the election of Argentina's president next October--or even run herself.

"She is a factor that frightens a lot of people because no one knows what she will do, what side she will take," said one non-Peronist politician, who asked not to be named. "And because she is who she is--the wife of Peron--she can never be discounted."

Peronist party leaders already have begun to prepare for their former leader's return. A party congress passed a resolution last weekend urging the military government to lift its political sanctions against her, and one of the two principal Peronist factions has already announced it will nominate her for party president.

Other Peronist leaders have gone further, asking that the military junta grant Peron a pardon, thus removing both military and court barriers to her possible candidacy. Despite the military's known antipathy to the woman whom it overthrew and kept imprisoned for more than five years, this possibility has not been ruled out by Argentine political leaders.

Peron has intensified the growing speculation and maneuvering with reclusion and a silence so absolute that the mystery of her intentions has increasingly overshadowed electoral politics. "She has still not made a final decision about her candidacy," said Juan Labake, a former Peronist congressman who is among those who claim to know the former president's wishes. "She would accept being president of the party. She could campaign for the Peronist candidate. She feels that for all the sectors to come together, they all have to feel loved and understood by her."

The ambiguities that such statements have introduced into Argentine politics are not easily understood by the Peronists themselves.

"Mrs. Peron must determine her level of involvement," said party leader Antonio Cafiero, one of the leading candidates for the Peronist nomination for president.

Asked what that could mean, he added, "I don't have the slightest idea."

So complex is the problem of accommodating Isabel Peron in Argentina's electoral politics that many of the principal Peronist and military leaders find themselves awkwardly seeking to twist the situation in unfamiliar ways.

While always careful to praise Peron as the surviving symbol of their movement, some Peronist leaders have appeared to seek subtly to sideline her political activity. Cafiero and Deolindo Bittel, the Peronist Party vice president, for example, have argued against a formal party request for a pardon, saying such an action would implicitly recognize the legitimacy of Peron's conviction on corruption charges and of her banning from politics.

Some military leaders, in contrast, are said to be inclined to grant the pardon to their old adversary or at least to lift the parallel military ban on her activities.

"They want Isabel to be completely free to be a candidate, because they think that will divide Peronism," said Labake.

Meanwhile, in the Radical Party, a moderate, middle-class-based group that is the other major contender in the presidential election, the renewed drama of Peron has been greeted with barely concealed satisfaction.

"It will be good for us if she returns," a leading Radical organizer said. "Isabel produces a kind of Pavlovian effect--as soon as she is here, all of the old enemies of Peron will come pouring out, and all the emotions of that terrible time will appear."

This contradictory sway of Isabel Peron over Argentine politics stems from the combination of her special status as political heir to the country's legendary three-time president and her own troubled and often bizarre course as president after Juan Peron's death in July 1974.

Installed by Juan Peron as vice president in part to avoid choosing among the myriad competing and sometimes violent factions of his populist movement, Isabel Peron never showed the political flair or attracted the personal following of Peron's celebrated second wife, Evita.

With Juan Peron dead, the Peronist movement split into factions under Isabel's leadership, and the government staggered from crisis to crisis as Argentina was rent by political violence and heavy inflation.

Isabel Peron was seen by many Argentines as weak and easily manipulated by unscrupulous advisers, most notoriously an astrologer and former policeman named Jose Lopez Rega, who organized right-wing paramilitary hit squads and allegedly misappropriated millions in government funds before fleeing the country in 1975.

Some of the divisions that are now at the center of Peronist politics first broke into the open during Isabel Peron's government.

During the past year the struggle between the two main factions has grown more focused and intense, and now hinges largely on the battle of two competing Peronist labor federations for control of Argentina's unions.

Most Peronists argue that Peron has no interest in becoming involved in the internal dispute and will not become active in the party until after it is resolved--if at all.

But none of the Peronist leaders seems to know for sure what their unpredictable former leader really plans.

"Her silence is unexplained, but that is a thing we are used to," said Labake. "It has been like that now for seven years."