In August some of the physicists at Met Lab isolated a microscopic amount of plutonium. It was a major development; the entire department buzzed with the news. This meant that it was possible to separate plutonium from uranium and thus produce a supply of it for the bomb. Met Lab was on the right track. In the meantime, Enrico Fermi and his team continued with experiments that would produce a chain reaction in the Pile.
Lena fed the information to Hans. He’d been elated with her sketch of the Pile, and he seemed fascinated by every new development. She also passed him the news that construction of the bomb and its materials would not be in Chicago. Production would relocate to the Clinch River in Tennessee and would be turned over to a private firm reporting to the Army. An experimental pile would be built in the Argonne Forest Preserve just outside Chicago, but the Met Lab scientists were just that, scientists and researchers, not facility operators. Compton had wanted to keep everything at the University, she told Hans, but he was overruled. People were fearful of an accident in such a heavily populated area.
In September, the Army appointed Colonel Leslie R. Groves to head the production effort, which was now called the Manhattan Project. Groves, a former West Pointer with the Army Corps of Engineers, had supervised the construction of the Pentagon building in Washington. When Groves took command, he made it clear that by the end of the year, a decision would be made as to which process would be used to produce a bomb.
Lena dutifully reported the news to Hans. Occasionally Hans would meet her in a black Ford, and they’d drive around the South Side. Other times they met in a coffee shop, always a different one. This time he drove to a diner where they sat at the counter. A fresh-faced boy with a white peaked cap took their order of iced tea for Lena, a chocolate milkshake for Hans. Leaning her elbows on the counter, Lena watched the boy make the milkshake.
“Do you have another car, a black sedan of some sort?” she asked.
Hans frowned. It took him a moment to reply. He shook his head. “No. Why?”
“Someone was following me in a black car. I did not know the make.”
“When?”
“Perhaps a week or so ago.”
“Where?”
“On 57th Street. In the morning. I was on my way to work.”
Hans arched his eyebrows. “Did you see who it was?”
She shook her head. “He was wearing sunglasses and a boater.”
Hans splayed his hands on the counter. “I have no idea.”
Lena looked over. “The man looked familiar. But I couldn’t place him.”
Hans shrugged. “Perhaps he just wanted to follow an attractive woman.” He smiled, but it looked forced.
The boy behind the counter brought their drinks. Lena reached for a straw and sipped her tea. Hans hadn’t made the slightest move towards her in the months they’d been working together. He’d been totally professional, although he clearly knew she’d been using her womanly charms on Irving. For a moment she wondered why he kept her at a distance, especially when he told her more than once how attractive she was. Then she decided it was better this way. Not only was he a Nazi, but any undue attention from him would give her something else to worry about.