BY CAROL ROSENBERG AND LESLEY CLARK

Retired State Department employee Walter Kendall Myers and his wife, Gwendolyn, told friends they had summer plans to take their 37-foot yacht north last weekend, up the picturesque coastline to New England.

Instead, the couple waits in a federal jail for trial, charged with 30 years of spying on the United States for the country's longtime antagonist, the communist regime of Cuba.

And friends and colleagues are left to reconcile the gregarious, well-read couple they knew with federal charges that allege a life of duplicity -- of shadowy intrigue involving coded messages to Havana and clandestine contacts with Cuba's spy agency.

''They were always very personable. Gwen told me about the yacht they were having built by this company in the Netherlands, that Kendall had retired,'' said Woody Reagan, who lived upstairs from the couple for more than a decade in The Westchester, a fashionable co-op near the Washington National Cathedral.

''They were planning to sail the Caribbean,'' he said. "I didn't know they'd be saying hi to Fidel. They never discussed politics.''

Even as Secretary of State Hillary Clinton ordered an assessment of any national security damage the couple may have caused, a week of interviews with those who knew them said they never mentioned Cuba.

Myers -- who goes by Kendall -- had two grand passions: Europe and sailing. Gwendolyn was an avid sailor, too.

In court Wednesday, but for matching navy blue jail uniforms, they looked like any other retirees, tan and thin. Kendall Myers had his trademark thick white walrus mustache and a bit of an academician's air. Next to him sat Gwendolyn, petite, with blonde hair turning to gray.

None of those interviewed detected the fawning affection for Fidel Castro ascribed to the couple in court documents -- Myers gushing after a 1978 visit to Cuba that Castro was a ''brilliant and charismatic leader,'' and decades later talking in a sting operation of a desire to sail ''home'' to Havana and teach at Cuba's intelligence school.

The FBI alleges long-standing ties to Cuba, saying in an affidavit that the pair agreed to spy after a Cuban diplomat from the country's mission to the United Nations visited them in South Dakota in 1979 or 1980. He had earlier invited Kendall Myers to visit the island, and Myers did so in 1978, praising the Cuban revolution in a diary the FBI uncovered.

A CIRCUITOUS LIFE

A Washington, D.C., native, Kendall Myers traced his family's roots through Gilbert Grosvenor, president of the National Geographic Society, to great-grandfather Alexander Graham Bell, credited with inventing the first practical telephone. At one time, the family had an estate in Coconut Grove near Kampong, the estate owned by renowned botanist David Fairchild.

Myers earned a doctorate in European Studies from Johns Hopkins University's prestigious School of Advanced International Studies, or SAIS, in 1972. His dissertation: A Rationale for Appeasement, on Britain's policy toward Nazi Germany before World War II.

Records suggest that the years preceding his involvement with Cuba were turbulent. Myers in 1975 crashed his car in Washington, killing a 16-year-old girl, The Washington Post reported. In 1977, he divorced the mother of his son and daughter.

He got a job at the State Department, his on-again, off-again employer for 30 years, working first as a contract instructor at the Foreign Service Institute, a training program that prepares diplomats for overseas assignments with history, politics and language classes.

What led him for a brief time to South Dakota, and the woman who would become his next wife and alleged partner in espionage, is not known. A South Dakota newspaper says that Gwendolyn Steingraber, a former legislative aide to then-South Dakota Sen. James Abourezk, was working at a state public-utilities authority. Kendall Myers was writing a biography about Neville Chamberlain, friends of Gwendolyn's told The Sioux Falls Argus Leader. Chamberlain is the former British prime minister and diplomat widely blamed for Britain's policy of appeasement toward Nazi Germany, which failed to avert World War II.

By 1980, the couple returned to Washington, where Gwendolyn found work as an analyst at Riggs National Bank. They married in 1982, and Kendall Myers began working again for the State Department -- at the urging of the Cuban government, the FBI affidavit says.

Across those years, Myers was an adjunct professor at the School of Advanced International Studies, a Washington institution along Embassy Row.

AREAS OF EXPERTISE

Former students say they, too, saw no signs of a secret life. There were ''no hints whatsoever,'' said 2009 graduate Aki Kachi, 27, who took Myers' Modern British Politics course. ``He never mentioned Latin America.''

''It was clear he wasn't really a fan of Margaret Thatcher,'' Kachi said. ``But you don't have to be a communist to not be a fan of Margaret Thatcher.''

At the State Department, Myers moved from the Foreign Service Institute to what would become an eight-year stint as an analyst at the Bureau of Intelligence and Research.

A fellow State Department retiree, Wayne White, said Myers' area of expertise -- Western Europe -- was rarely in the spotlight, so his colleague often found himself relegated to rounding up speakers for new employee orientation classes.

White, who considered Myers ''affable, gregarious and incredibly pleasant,'' said he and co-workers are bewildered at the notion that Myers would ``develop a sympathy for an otherwise loathsome Communist regime.''

The FBI says it was at the Foreign Service Institute that Myers met his first Cuban government official, a U.N. envoy lecturing there during the Carter administration, which was experimenting with engagement with Havana.

Was Myers a bored bureaucrat? A disaffected, wannabe diplomat? Fading hippie? He struck people as more of an egghead academic than the fiery ideologue FBI documents suggest the sting operation exposed.

London Daily Telegraph reporter Toby Harnden met him in 2003 to discuss developments in Northern Ireland. Harnden, the paper's Washington correspondent, had written a book on the Irish Republican Army. Myers invited him to lunch. They analyzed an upcoming election, what the Irish political party Sinn Fein would do.

''He was good company. He definitely saw himself a diplomat,'' Harnden said. He said he viewed his host as ``quite English, actually. Tall, academic, stooped.''

The same year, the FBI claims, the professor and his wife took vacations to Mexico and Brazil to meet clandestinely with Cuban handlers.

But Myers had his sights on becoming a full-fledged diplomat, not an office-bound paper-writing analyst. He sought out Northern Ireland expatriate Michael McDowell at social events in Washington in 2005 and plainly told him he aspired to become the next U.S. envoy to to that country.

McDowell, now a consultant at the Bill and Melinda Gates Foundation, thought Myers' aspirations ''slightly eccentric.'' These were the Bush years, and McDowell assumed that a Republican appointee would get the job. Myers and his wife are both registered Democrats.

McDowell declared himself ''gob-smacked'' by the emerging FBI narrative of the couple's life of duplicity. He had the Myerses to dinner one night with a Lord in Britain's House of Parliament, and he said the couple left the impression they had no children.

In court last week, though, their lawyer asked the judge to grant the couple bail so they could see their children, two each from earlier marriages. Gwendolyn Myers' middle-aged son, Brad, was the lone one there. He declined to speak with reporters.

''He never at all mentioned Cuba,'' said McDowell. "I'm a Canadian citizen, I traveled to Cuba. But if you think about it, that would make sense, wouldn't it? It was probably the last thing he wanted to talk about.''

FBI agent Brett Kramarsic, an eight-year employee who specializes in counterespionage, suggests in the affidavit that Cuban intelligence agents targeted Myers as ripe for recruitment during his 1978 visit. His guide for the trip, Kramarsic writes, worked at Cuba's Foreign Service Institute.

LEFT TO WONDER

In the week that followed the arrest, friends and colleagues have reached for some kind of an explanation. McDowell says -- with hindsight -- that the tale the FBI has spun reminded him of Kim Philby, the British intelligence double agent who betrayed his country to Josef Stalin.

The same thought occurred to White, Myers' retired State Department colleague: "He seems to resemble this pattern of ideological upper-class obsession for a supposedly idyllic totalitarian system.''

Moreover, counterintelligence experts wonder which U.S. national security secrets the Myerses may have compromised.

Kendall Myers had a Top Secret clearance. Their alleged spy work started in the Cold War, causing people like McDowell to question whether any information they gave Havana helped the war effort in Angola or was repurposed and peddled back to the Soviets.

Clinton has ordered an internal investigation. Federal prosecutors said in court last week that they'll assess the damage and, if there is a conviction, use that information during the penalty phase of the trial.

One of Myers' former students, Tom Murray, said he found clues in lectures that Myers may have admired Philby and other prep-school elites who in the Cold War became Soviet double agents to "save Europe.''

''Myers favored the underdog, according to my notes,'' Murray, who studied at the School of Advanced International Studies in the 1990s, wrote in a blog posting on The Daily Beast. 'Besides his admiration for Soviet double agents, he was a Neville Chamberlain man. While he compared Winston Churchill to the liberals' bogeyman of the early 1990s, Jesse Helms, Chamberlain was 'savvy, knowledgeable' and 'faced the situation as best he could,' despite the obviously flawed outcome.''

At a 2006 SAIS lecture, Harnden was there as Myers assailed then-British Prime Minister Tony Blair for marching in lockstep with President George W. Bush toward the war in Iraq.

Myers had argued that Britain should have aligned with Europe in questioning the necessity of the war. The remarks triggered news articles raising questions about the State Department employee criticizing Blair.

Such talk was not unusual in the apartment building where the couple lived. ''Nobody was happy with the last administration,'' said neighbor Jacqui Gallagher.

Still, Myers retired 11 months later.

In April, the couple reportedly told a covert FBI operative posing as a Cuban intelligence agent that they enjoyed retirement -- but missed their work with Cuba.

They had stopped traveling after returning from a professorial exchange with China in 2006, worried that work had put Kendall Myers on a "watch list.''

''You, speaking collectively, have been a really important part of our lives,'' Kendall Myers was quoted as saying. "I mean, we really love your country.''