Tolkachev was 54 years old in 1981. He suffered from high blood pressure and tried to pay attention to his health. He drank alcohol only rarely. He was usually up before dawn, especially in the long winter, according to letters he wrote to the CIA. Every other day during the week, he got out of bed at 5:00 a.m. and went for a run outdoors, if it wasn’t raining or biting cold. In one letter to the CIA, he described himself as a morning person. “You probably know,” he wrote, “that people are sometimes divided into two different types of personalities: ‘skylarks’ and ‘owls.’ The first have no trouble getting up in the morning but start getting sleepy as evening approaches. The latter are just the opposite. I belong to the ‘skylarks,’ my wife and son to the ‘owls.’”

Tolkachev lived in a comfortable apartment in a building he shared with the Soviet aviation and missile elite. His neighbors included Valentin Glushko, the principal designer of Soviet rocket engines, as well as Vasily Mishin, who led the Soviet effort, ultimately unsuccessful, to build a lunar rocket. But Tolkachev was a loner. He had once socialized with workers at his laboratory, he told the CIA, but now, “possibly because of age, all these friendly conversations started to tire me and I have practically ceased such activities.” Above Tolkachev’s kitchen door was a crawl space where he stored his camping tent, sleeping bags, and building materials—as well as his spy equipment from the CIA. His wife Natasha, slightly shorter than Adik, was not agile or tall enough to reach it, and his son Oleg had no reason to.

Adik and Natasha lived and worked in the closed cocoon of the military-industrial complex, a sprawling archipelago of ministries, institutes, factories, and testing ranges. Tolkachev had the highest-level access to state secrets. Their public behavior was governed by survival in the Soviet party-state system, which dictated conformity. By day, they played by the rules. By night, their private feelings were vastly different.

Their thinking was forged in the sorrow and loss of Natasha’s childhood, which she had spent without parents due to Joseph Stalin’s purges, a loss that propelled Adik into the world of espionage. After a series of show trials in Moscow beginning in 1936, the purges sliced through the party elite, and expanded later in the summer and into the autumn of 1937 with wave after wave of suspicion, denunciation, arrest, and execution. One of the largest was the kulak operation, referring to the more prosperous farmers who had been forced off their land during Stalin’s disastrous forced collectivization of agriculture, with more than 1.8 million of them sent to prison camps. When the kulaks neared the end of the standard eight-year prison term, Stalin feared a wave of disgruntled and embittered people coming home. The hammer fell with a secret police order, No. 00447, in July 1937, which set the pattern for the mass killings of the following two years. The document ordered arrests by quota—thousands and thousands at a time—in specific categories such as “kulaks, criminals and other anti-Soviet elements.” The categories were so broad as to apply to almost anyone. People were arrested and executed for the slightest indiscretion, so they became extremely guarded in what they said in public; a single stray comment could be reported and lead to arrest, with the charges entirely arbitrary.