Years later when asked about that evening, Jean said only, "It was serious from the start." She would remember Koval as slender with broad shoulders, standing about six feet, appearing very masculine. He had short, straight brown hair, brown eyes, and very full lips, making his broad smile all the more attractive. A clean-cut guy, only two years out of the US Army, he typically wore a dark navy blazer and khaki trousers. And though he never seemed to be clothes conscious, he looked smart, urbane, more like a seasoned New York intellectual than a former soldier born and raised in Iowa, which he was. Still, it must have been his Midwest upbringing that caused traces of innocence to seep through his streetwise exterior. Or perhaps it was his curiosity about everyone and everything that surrounded him. Koval was like a cat, always watching and ready to act, with a playful mix of enthusiasm and caution.
When asked about Koval, Jean would say he was suave and spirited, but also cut from rugged rock. Few people knew his solemn side, which she believed may have been rooted in a distressed childhood. That also would have explained why he avoided detailed discussions about his past. However, he did tell her that he was born in Sioux City on Christmas day in 1913, that he was seventeen when he left home, and that shortly thereafter both of his parents had died. As an only child, that was the end of his family, he told her. She listened and had no reason to doubt his story. Besides, there was so much more to talk about, such as baseball, his ultra-passion. Koval could reel off the history and complete stats of every big-league pitcher in 1948. He was even renowned among friends for his skills as a shortstop.
During the months of planning her life around him, Jean was not on the hunt for evidence of anything negative. Why would she be? Occasionally she noticed that he went out of his way to validate his sincerity. He also had a tendency to suddenly be silent, as though a part of his machinery had abruptly shut down. He was always precise, never diverging from the norm and never saying more than he meant to. And he was very punctual.
But on September 19, he was late—and he seemed quite agitated about it. From the start of the evening, he was not the smooth, charming companion Jean had known thus far, and the longer they stayed at the Grand Central Palace the more troubled he seemed to be. Possibly to ease his anxiety, they were on the move constantly, visiting every exhibit, but always returning to "Man and the Atom," likely to be certain they hadn't missed the arrival of his friends. Nothing could distract him, not even the popular model of a 200,000-volt generator, used in atomic experiments, which had the capability of creating fierce electrical energies; it was on display in a compartment where viewers could enter and watch their hair stand on end.
Koval wasn't interested. He seemed like an actor who had forgotten his lines. Anxious. Distant. Alone. The exposition shut down at midnight and the couple stayed until the last second. No friends, no former colleagues from Oak Ridge, no war buddies ever arrived. Then, taking the subway back to the borough of the Bronx, where each of them lived, they had what Jean would later describe as "a lovers' quarrel, which had never happened before." With time, the reason for the spat would fade, but not the memory of how he "seemed to be picking a fight." When he walked her to the apartment where she lived with her parents, whether he said "good night" or "good-bye" was a detail she could never recall.
In the weeks ahead, Jean left him alone, as advised by her brother Leonard and guided by her own instincts. Such a standstill must have required remarkable discipline, especially considering the exchanges they could have been having about the two rousing battles consuming front-page news: one in sports and one in politics. In baseball, two underdog teams were headed to the 1948 World Series: the Boston Braves, which hadn't won a pennant since 1914; and the Cleveland Indians, absent from the winner's circle since 1920. It was the kind of contest that Koval, as a dedicated champion of the underdog, would closely follow. And in politics, there was a continuing blast of intriguing headlines about Soviet espionage in New York, including atom bomb spy networks. One headline read, "Spies in U.S. Are 'On Run.'"
Still, Jean resisted a daily urge to hear his voice. And when she finally had to talk to him and made the call, the landlady answered, telling her that Koval wasn't there and wouldn't be back for a while, a long while—perhaps never again. He didn't live there anymore, she said, and at that very moment he was on a ship heading to Europe. He had left "yesterday morning, with only a duffle bag."
For Jean, it must have seemed like sudden thunder on a clear day. After calling her brother, who said he knew nothing about Koval's leaving town, she contacted the man she believed to be Koval's closest friend, Herbie Sandberg. He confirmed that Koval had departed from New York on October 6, with a plan to work as a manager at the construction site of an electric power plant in Poland. Sandberg didn't know when his friend would return nor did he have a forwarding address to offer her. He did know that Koval left on a transatlantic liner called the SS America, from Pier 61, and he remembered that it had rained that day. But nothing more.