When Daniel and Vivian Rafuls came to Miami from Cuba three years ago, they were warmly welcomed by exiles as examples of Fidel Castro supporters who had grown disillusioned with communism.

Daniel, 40, a professor at Cuba's top military college, was soon interviewed on Radio Marti and joined the Cuban Military Research Center, a group of armed forces defectors who study the island's military.

Vivian, 42, who taught atheism at the University of Havana, lectured at a University of Miami seminar on Cuba last year and found work through friends as a substitute teacher at Kinloch Park Elementary.

But the Rafuls got an even warmer welcome when they returned to Cuba.

A ``companero from State Security called a meeting of Vivian's former university co-workers in January and presented her as a ``true revolutionary who had been ``on a mission abroad with her husband, said two Cubans present.

The Rafuls were spies, just two of the 16 men and women identified as Havana intelligence agents in Miami over the past six months by Cuba's State Security Department or the FBI.

Some appear to have been career intelligence officers. Others were informers or true Castro opponents at one time, threatened by Cuban security agents with jail and worse for them and their families to force them to become collaborators.

Their primary task was to penetrate exile groups and alert Havana to violent plots. But they also instigated conspiracies and sowed dissent among
Castro has long spied on South Florida's exile community, and over the years knowledgeable exiles have estimated that he maintains some 300 trained agents, collaborators and knowing or unknowing informers here at any one time.

``It's been going on almost virtually since the day Fidel Castro came into power,'' said Skip Brandon, a retired FBI agent who spent 10 years of his career chasing suspected Cuban spies in the Miami area.

``South Florida is kind of interesting because the deep cover agents don't need the kind of intensive language and other training that a Russian might have needed,'' Brandon said. ``Someone from Cuba could come right in and go right to work -- blow right through the doors.''

The FBI office in Miami has one Foreign Counter-Intelligence squad with 12-14 agents assigned exclusively to tracking suspected Cuban agents, and another that follows all others, mostly Russians and Israelis.

Cuba, China, Iran, Israel, France and Russia were listed as the nations most active in industrial espionage against the United States in a CIA report to Congress in 1996.

But Havana's unveiling of six agents since January and the arrests of 10 other suspects in Miami Sept. 12 have focused fresh attention on the spies, their tales of exile terror plots and exile charges of Cuban provocations.

``When Castro accuses exiles of terrorism, their defense could be stupidity or entrapment, said one State Department official, referring to recent Havana charges that exile leaders financed a bombing campaign against Cuba from 1992 to 1998.

THE RAFULS
Striking couple infiltrated activisits

Daniel and Vivian Rafuls' telephone answering machine is still working at their apartment on Southwest 17th Terrace. There's furniture in the apartment, food in the refrigerator and clothes in the closets.

But FBI agents began picking up their phone messages and mail, according to friends and neighbors who were interviewed by the Bureau, soon after the Rafuls disappeared -- just six days after the 10 accused Miami spies were arrested.

The FBI declined comment on the Rafuls or their links to the 10 that made them bolt back to Cuba. ``There are many related activities that are still under investigation, and at this point the FBI is not commenting,'' said spokesman Mike Fabregas.

But the Rafuls appear to have been ordinary spies, with no known contacts with radical exiles who support violent attacks.

Daniel was a professor at the Cuban military's Jose Antonio Maceo Interarms Academy when he picked up a U.S. passport -- son of a Cuban couple living in the U.S, he was a citizen by birth -- and left for Miami in late 1995.

Vivian and their adopted 10-year-old son followed Daniel in 1996. Because she was head of the Communist Party cell in the university's philosophy department, her departure sparked a scandal. The cell later expelled her.

They made a striking family, friends in Miami said. He was tall and handsome, she was blond and green-eyed. Their son was so obviously of indigenous descent -- she claimed he was the son of a Peruvian guerrilla leader -- that Vivian complained Miamians would stare at him.

Daniel first moved in with a Miami uncle, Arnold Rafuls, who last week said he knew nothing about his nephew's whereabouts. ``He told me they were moving to Orlando but never wrote. The ingrate! After all we did for him!

Daniel and Vivian started out working at a Wal-mart store until he found a job as a waiter at Botin, a Spanish restaurant on Coral Way, and she found the part-time job at Kinloch, friends said.

``She told me they were having a tough [economic] time, said Enrique Patterson, a Dade County schoolteacher and former Havana university professor who met her at the University of Miami seminar on religion in Cuba last September.

But over time, Daniel moved into exile activist circles, going on Radio Marti at least once to talk about the Cuban military and joining the Cuba Military Research Center, said center director Frank Hernandez Trujillo.

Made up largely of defectors from Cuba's armed forces and Interior Ministry, the center says it studies the military's possible role in any transition to democracy and sends medicines and other humanitarian assistance to veterans of Cuba's Afican wars.

Rafuls told friends that he had become disaffected with Castro, but he never advocated violence against Castro or asked the kinds of probing questions that might have made him suspect a spy, Hernandez-Trujillo said.

``We had a decision to make a long time ago. Either we don't talk to these guys [defectors who might turn out to be spies] or we welcome them. We decided to welcome them because we do everything legally, he said.

THE DISSIDENTS
They testified in Cuba bomb trials

Oscar Madruga, Juan Francisco Fernandez and his wife Olga make unlikely spies.

Madruga, 66, and Fernandez, 63, are sickly veterans of Castro's prisons, having served 14 and 10 years, respectively, in the 1960s and '70s. They later became some of the earliest members of the human rights movement in Cuba.

Fernandez visited Miami four times starting in 1986. On his last visit, in spring 1998, Madruga was with him. He also brought his 21-year-old daughter and left her here.

``We took him right to the hospital when he came last year because he had emphysema, said Rolando Borges, who met Fernandez in Castro's prisons and now heads the Miami-based Ex-Club of former political prisoners.

But Fernandez was ``arrested after returning to Cuba last June, and the State Department even mentioned his case in its 1998 report on Cuban human rights abuses.

Cuban prosecutors at the trials of two accused Salvadoran terrorist bombers last month showed videotapes of Fernandez and Madruga saying they were long-time state security agents who had been recruited by Borges to bomb targets on the island.

Fernandez's wife did not testify at the trial but did give interviews on Cuban radio confirming her role as a spy.

One of the targets listed by Fernandez: The mausoleum that holds the remains of Cuban-Argentine guerrilla leader Ernesto ``Che Guevara in the central provincial capital of Santa Clara.

Fernandez claimed Borges taught him how to make a bomb and told him that ``a Central American man would call him after he returned to Cuba, give him the password, ``I have the medicines, and hand over explosives.

One of the Salvadoran bombers, Otto Rene Rodriguez, later telephoned him in Cuba and gave him the password, Fernandez said. Rodriguez was arrested on June 10.

Fernandez offered no hard evidence for his allegations, and it's not known why he and and Madruga did not testify in person at the trial instead of through a video.

Rodriguez and the other Salvadoran, Raul Ernesto Cruz Leon, accused in six bombings against Havana tourism centers in 1997, were convicted on terrorism charges and were sentenced to death by firing squads.

Borges told The Herald he had done nothing illegal and that Fernandez and Madruga were lying -- no doubt under threats by Castro's police against them and their families.

``These are two poor viejos [oldsters] who were broken in prison, Borges said. ``Prison is hard and the government terrorizes you.''

Exiles close to the Ex-Club told The Herald, however, that Fernandez and Madruga had indeed talked about bombs with Ex-Club members during their last two visits to Miami.

``Of course they talked about C-4 explosives and things, said one exile active in the Ex-Club, ``perhaps not with Borges himself but certainly with some of the more radical members of the Ex-Club.

Fernandez and Madruga ``were always talking about sabotage when they came to Miami, according to one human rights activist here who said he avoided them because of ``their troublesome talk.

A third Ex-Club member said Fernandez and Madruga began acting secretively during their last visit to Miami, telling friends that they had ``returned to the armed struggle against Castro.

Borges acknowledged to The Herald that he paid for the hotel room of Col. Guillermo Pinel Calix, then head of Honduran army intelligence, when Pinel Calix visited Miami in 1994, but claimed to have known nothing about the colonel's mission here.

The Herald reported last May that Pinel Calix was in Miami to negotiate a deal: Cuban exiles would pay a $100,000 bribe to Honduran military officers in exchange for permission to use their country as a secret base for training commandos and launching attacks on Cuba.

The Herald report also identified the deal's mastermind as Luis Posada Carriles, a Cuban exile living in El Salvador who has publicly admitted sending the two Salvadoran bombers to Cuba.

Said Borges: ``I cannot deny my anti-Castro vocation. We help, in any way, anyone who does anything against this dictatorship. We have to support that struggle. But we do nothing knowingly violent.

THE MULE
He claimed he was recruited by CANF

Percy Francisco Alvarado, a stocky, 49-year-old professor of Marxism at the University of Havana, opened his testimony at the Cruz Leon trial last month with a statement that sent a buzz through the audience.

``To the Cuban American National Foundation, I am Agent 44. But to the Cuban organs of State Security I have been Agent Monk for the last 22 years, he declared in a forceful voice.

Alvarado testified that, during one of his many trips to Miami between 1993 and 1995, CANF officials recruited him to carry out several missions in Cuba, from locating likely targets for bombings to smuggling two bombs into Havana.

The son of a Guatemalan Marxist who moved his family to Cuba in 1960, Alvarado used his Guatemalan passport to go to Miami as a ``mule, charging exiles a fee to take back cash and medicines for relatives on the island.

The CANF officials he identified -- President Jose Francisco ``Pepe Hernandez, human rights activists Luis Zuniga and board of directors member Arnaldo Monzon and Roberto Martin Perez -- all denied the allegations.

Alvarado also identified the men who gave him the two bombs as Posada Carriles and Gaspar Jimenez, sometime chauffeur and guard for CANF Chairman Alberto Hernandez.

But radical anti-Castro exiles who met Alvarado portrayed him as a provocation agent, always offering himself for illegal or violent actions inside Cuba and egging on radical exiles to act.

``He was always dandole cuerda to some guy or some conspiracy, said one of the exiles, using Cuban slang for ``winding up, as in winding up a mechanical toy.

Alvarado once brought what he claimed to be an original letter from Cuban independence hero Jose Marti and announced he wanted to sell it to CANF, said Victor Hernandez, a friend who let Alvarado stay in his Miami home several times.

Another exile recalled Alvarado asking for thousands of dollars in cash to finance what he portrayed as a secret cell of Castro opponents within the Cuban armed forces and the Interior Ministry.

``Some of us didn't pay attention to him, the exile said. ``But I know that others did fall in his traps.

PROVOCATION?
Castro agents accused of instigating violence

Havana's decision to unveil Alvarado, Madruga, Fernandez and his wife as spies at the trials of the two Salvadorans -- if indeed they were telling the truth -- did not surprise U.S. officials who monitor Cuba.

``First, they wanted to present the strongest possible case against the Salvadorans. Second, they wanted to embarrass the exiles. Third, they wanted to push us to take action against exiles who do engage in violence, said one official who followed the trials.

Whatever plots Havana's spies may have instigated in Miami, the official added, ``provocations from Castro spies can never be a defense for exiles who engage in illegal actions from U.S. territory.

But that's not the way that Francisco Avila sees it.

A Miami tile setter, Avila has admitted to working for Cuba and later the FBI, until 1992, at the same time he was serving as military chief for Alpha 66, which advocates the violent overthrow of Castro.

``Castro's agents here instigate actions so he can then paint the exiles as terrorists, as ultra right-wingers, and take attention away from his own terrorism against Cubans, he said.

Avila said his own Cuban bosses gave him cash in the late 1980s and early 1990s to finance three boat-borne exile attacks on Cuban coastal installations known as ``sail-by-shootings.

And he recalled the case of a Cuban dissident who came to visit Miami in the early 1990s, ``simply walked into CANF headquarters and announced that he wanted explosives and money to bomb Cuba.

Pepe Hernandez patted the visitor for a hidden recorder, Avila said, then ``explained CANF's peaceful interests and threw him out. On the way out he ran into [Luis] Zuniga, and Zuniga gave him the same lecture.

The visitor later decided to stay in Miami and confessed to CANF officials and the FBI that Cuban State Security agents had pressured him to become a spy and try to provoke the CANF officials, Avila said.

THE BETRAYER
He may have provoked roommate's suicide

Cuban state security officials have revealed much more about Alvarado, Madruga, Fernandez and his wife than about the man who may well have been one of their most successful spies in Miami in recent years.

Ivan Luis, then 48, and his wife, Maria Elena Reyes, arrived in Miami Beach July 9, 1993, aboard a boat with 25 other refugees. They told a tale of long days at sea until they landed in the Bahamas, received money from relatives in Miami and hired a smuggler to bring them here.

``The bathers received us well. They all came over to greet us. They talked to us, they applauded us, they gave us food, Luis told a Herald reporter who interviewed him on the beach.

Over the next five years Luis quietly penetrated CANF and the Ex-Club, the Cuban Military Research Center and the Union of Free Soldiers and Officers, a group headed by former Cuban air force Col. Alvaro Prendes.

He even served on the board of directors of the Civic Movement for Human Rights.

``He was everywhere, said Channel 23 reporter Rafael Orizondo, who first identified Luis as a spy last May, soon after Luis quit his job as chauffeur for a medical service van and vanished.

Luis was later identified as a lieutenant colonel in the Cuban armed forces and his wife, who apparently had returned to Cuba the previous year, as a captain in the Interior Ministry.

Luis left behind a stunned roommate of several months, Jose Enrique ``Cucu Bringuier, a poor, 79-year-old former political prisoner and member of the Ex-Club, as well as a $5,000 telephone bill in Bringuier's name.

Miami human rights activist Ruth Montaner recalled Bringuier telling her ``I've been living with a spy! over dinner at the Versailles Restaurant just before Orizondo broadcast his story.

A few weeks later, in late June, Bringuier telephoned her to say he was distraught over several ailments but had ``something urgent to tell me, Montaner said. They never met.

That weekend, on June 21, Bringuier's body was found on the bed of his Miami apartment, a thin trickle of blood beneath the spot on the chin where he had shot himself.

Herald staff writers Rick Jervis and Lisette Garcia contributed to this report.