The Shadow Dossier

Klaus Fuchs left Germany in 1933 as a young physicist and a committed communist, one step ahead of the Nazi regime that had already marked him for arrest. Britain took him in. By the outbreak of the Second World War, he had built a career as a gifted theoretical physicist and had even been naturalized as a British subject, despite a brief internment as an enemy alien in the war's early, suspicious months.

By the 1950s, the British public knew the outline of a scandal, even if the details took decades to fill in. Four Cambridge-educated men, recruited as idealistic young communists in the 1930s, had spent their careers burrowing into the heart of British intelligence and diplomacy while secretly serving Moscow. Guy Burgess and Donald Maclean fled to the Soviet Union in 1951. Kim Philby, the most senior of them, was unmasked and defected in 1963. Anthony Blunt, an art historian with a royal appointment, confessed privately in 1964 and was only named publicly in 1979.

In the summer of 2010, FBI agents fanned out across the suburbs of New York, Boston, Seattle, and northern Virginia to arrest ten people who had spent years building unremarkable American lives. They coached soccer, wrote for magazines, worked in finance, raised children in split-level houses with mowed lawns. Neighbors described them, almost without exception, as friendly and forgettable.

In July 1961, at Cliveden, a grand country house on the River Thames owned by Lord Astor, a group of guests gathered for a weekend. Among them was John Profumo, the Secretary of State for War in Harold Macmillan's Conservative government, and his wife, the actress Valerie Hobson.

In the late 1950s, a senior officer in Polish intelligence began secretly sending letters to Western intelligence services. He signed himself Sniper. He was Michał Goleniewski, and among the information he offered was a warning that the Soviet Union had a source inside the British naval establishment, someone with access to secrets about submarine detection and underwater weapons.

Oleg Gordievsky was a career officer of the KGB, the Soviet Union's intelligence service, and the son of a KGB officer himself. But in the 1960s, while stationed in Denmark, he watched Soviet tanks crush the Prague Spring in Czechoslovakia in 1968, and something in him broke with the system he served.

In early 1962, the Kennedy administration was still recovering from the humiliation of the Bay of Pigs, the failed invasion of Cuba by CIA-trained exiles the year before, which this dossier has covered in an earlier file. Fidel Castro was still in power, closer than ever to the Soviet Union, and senior officials in Washington were under pressure to find a way to remove him.

In the early 1950s, American intelligence officials were alarmed by reports coming out of the Korean War. Captured American soldiers were appearing in propaganda broadcasts, confessing to crimes they almost certainly hadn't committed and praising their captors. The word brainwashing entered the English language, and inside the Central Intelligence Agency, a fear took hold: what if the Soviet Union and China had found a way to control the...

A Senate investigation uncovered assassination plots, illegal domestic surveillance, and MKUltra, forcing the creation of America's modern intelligence oversight system.

A military-grade nerve agent on a door handle nearly killed a former double agent, and months later killed a woman who had nothing to do with any of it.