GRAHAM GREENE knew the difference between decent and indecent, and in Cuba he reveled in both. His life held an intoxicating mixture of literature, espionage, revolution and sex. His death April 3 provoked generous tributes from all over the world, yet few spoke of the erudite and libidinous spirit that characterized "Our Man in Havana."

Greene enjoyed "the louche atmosphere," as he described the Havana of Fulgencio Batista, especially the Shanghai Theatre. It offered "a nude cabaret of extreme obscenity with the bluest of blue films . . . . There was a pornographic bookshop in the foyer." According to Lisandro Otero, a Cuban writer who befriended the British author, "They told dirty jokes there, and it was filled with pimps and their prostitutes. Greene was interested in sex. In life."

Otero, who escorted Greene around the countryside in those days, recalls Greene for his enthusiasm for the country and his aid to its revolution. Otero lives in Miramar, a district of Havana with quiet streets, well-tended gardens and elegant homes. The 363 houses that haven't been converted to schools or government offices are mainly occupied by the capital's privileged class and foreigners. The walls in Otero's second-floor study are packed with books and photos, most prized among them one of him and Greene. In the spring of 1957, just a few months after Fidel Castro began the final two-year assault on the Batista regime, Greene came calling again.

"Through a series of intermediaries," said Otero, "I was asked if I knew anyone in the resistance, that a British writer was in town wanting to interview Fidel in the Sierra Maestra. I was a cub reporter at the time." Otero arranged a dinner meeting at El Chico, a small restaurant on the edge of Havana, between Greene and members of the lucha clandestina, the clandestine movement. One of the diners was Nydia Sarabia, who was introduced to Greene under a pseudonym.

"We coordinated his trip to the Sierra over our meal," Sarabia told me when we spoke a few months ago at her neat and roomy apartment in Vedado, a bustling section of Havana. "He wanted to interview Fidel, and he said he wanted to write two books, one about Havana and the other about Santiago de Cuba," a major city on Cuba's southeast coast. Sarabia and the others wanted Greene's assistance in the revolution.

"Natalia Bolivar {another participant in the dinner} had a suitcase of warm clothes she wanted carried to Santiago. At the time, Batista's police were checking the airport for rebels. Greene was perfect for the job. He was tall, lightskinned, obviously foreign, and he looked like he knew nothing of what was going on. He agreed to take the suitcase with the pullovers and leather jackets on board. In the Sierra it was very chilly at night, and these clothes would help the guerrillas. I was to be on the same plane as him, but we were to pretend we didn't know each other."

Sarabia, who later became a journalist and Jose Marti scholar, split her time between Havana and Santiago during the revolution. She told me that Greene confided in her suspicions that a Havana friend of his, a Time reporter, was with the FBI. "Greene arrived at the airport in a Jaguar for the flight," Sarabia recalled. "Mysteriously enough the Time reporter showed up for the same flight as well. Greene and I never made eye contact the whole trip."

In Santiago, Sarabia got word that the reporter was not to be trusted. "I overheard him in the lobby of the Casa Granda Hotel, talking on the phone with the SIM {Servicio Inteligencia Militar}. We learned that SIM had transmitted to the reporter a conversation between Greene and me.

"Greene took the suitcase full of clothes by my aunt's house -- that was the appointed rendezvous spot -- but he didn't stop there because he thought he was being followed. Finally at 10 the next morning we were able to link up and get the suitcase." At that secret meeting, Greene met with Jacinto Perez, the nom de querre of Armando Hart, now Cuba's minister of culture and a politburo member.

"The city was surrounded with Batista's army, and we didn't know if we could get Greene into the Sierra to see Fidel. We also told him about the British planes Batista was buying to bomb the rebels and civilians in the Oriente." (When Greene returned to England, he persuaded a friend in Parliament to raise the issue; as a result Britain refused to export any aircraft to Batista.) Meanwhile, the interview was off. The Time reporter, Sarabia learned, was an informer, a suspicion Greene himself noted in his autobiography. "Instead of sticking around," Sarabia said, "Greene left for Africa. He said he was going to interview the Mau-Mau guerrillas.

"Greene never knew my real name. Do you have his address? I'd like to write him now after all these years."

Greene returned to Cuba many times during the following decades. "Our Man in Havana," his dark and funny intrigue about Britain's espionage service, was set in the last months of Batista's dictatorship when "the president's regime was creaking dangerously towards its end." Through Wormold, a vacuum cleaner salesman and imaginative intelligence recruit, Greene mocked villainous police states and civil spies.

One afternoon last fall, a dog-eared copy "OMH" in hand, I took myself on a tour of Greene's Havana. The Sevilla-Biltmore right off the Prado, now the Sevilla, is under renovation, with hopes that it will again entertain guests in time for this August's Pan American games. The Victoria, where one of Wormold's subagents was shot, is now a handsome hotel, run by Spaniards. The Tropicana, Havana's elegant night spot where Wormold took his teenage daughter Milly for her 17th birthday, still presents a boisterous and elaborately choreographed show full of the enjoyably vulgar excesses the country officially eschews. The Inglaterra, where Wormold's secretary Beatrice spent her first night in Havana, looks better than ever, having recently emerged from a rooftop-to-cellar overhaul. Its ornate dining room with gilded walls and chandeliers hanging from high ceilings reminded me of a San Francisco hotel. That evening in the adjoining bar where a jazz quartet played, Ella, a tourist from Belgium, sat alone at a table. She was reading "OMH." I flashed my copy and sat down for a drink. "This place has acceptable decadence," she said. "I like it."

"That's all very well and good," I replied, "but we should really leave. Ella, don't you see?" I said, waving my own "OMH" in the air, "This was Graham at his most verdant. We must find the Wonder Bar," a saloon at the corner of Prado and Virtudes where Wormold routinely drank with Dr. Hasselbacher, a German emigre killed by Batista's goons.

The Inglaterra bartender, who seemed of age, had never heard of such a place, but Martinez, the percussion player in the house band had. "There were prostitutes downstairs and drunks upstairs. You'd find drugs, the Mafia, bingo and dogs. Strippers and music. You could buy lottery tickets, you could buy anything."

"Are you sure it was called the Wonder Bar?"

"Absolutely," Martinez said. "I used to go there."

Ella and I followed his directions and entered a dark bar with loud pop music blaring from erratic speakers. Our waiter, who was old enough to know, said it had never been known as the Wonder Bar. And to make matters worse, 37 Lamparilla street, where Wormold lived and sold Atomic Pile Suction Vacuum Cleaners, doesn't exist. The addresses skip from 35 to 39. Once, however, I thought I glimpsed Wormold's ancient Hillman tooling along the Maelcon.

Greene always had a fascination with strong leaders, which accounts, in part, for his attraction to Fidel Castro. After one visit, Castro gave Greene a painting he had done. It reportedly hung in the living room of the French house Greene called home for most of the last 25 years. "I have never hesitated to be 'used' in a cause I believe in," he wrote of his tiny part in the Cuban revolution, "even if my choice might be only for a lesser evil."

Still, he voiced nagging doubts about Fidel and uncertainty about the upheaval he brought to Cuba. "I admire him for his courage and his efficiency, but I question his authoritarianism," Greene told a French interviewer in 1983. "All successful revolutions, however idealistic, probably betray themselves in time," Greene added. "Cuba may well become the real testing ground of communism."

Tom Miller, author of "The Panama Hat Trail," is writing a book about his travels in Cuba, to be published by Atheneum.