Dr. Lawrence muttered under his breath. Several minutes later, he relinquished the stool to Ruth. He motioned for General Groves and Nora to follow him. When they were out of earshot he said, “As much as I don’t want to suggest this, we are going to have to pull one of these apart and get a look inside. There must be some kind of contamination or some foreign matter that’s causing the results we’re seeing.”

General Groves’s jaw was set and his lips formed a straight line. “The timing couldn’t be worse.”

“I know, but what choice do we have? We must get to the bottom of this and improve the output, and soon.”

Nora contented herself to stay in the background. Neither Groves nor Lawrence had asked her opinion, nor was she anxious to share her thoughts. The general remained silent so long, Nora wondered if he would answer at all.

“Do it,” was all he said, and he marched off the floor and out of the building without another word.

Dr. Lawrence watched after him. “Don’t worry. We’re all under a great deal of strain. Keep doing what you’re doing. We made some design changes in the Beta calutrons that should result in a more highly enriched product. We’re on the right track.”

“My girls are working their hardest. We won’t let you down.”

“I know. After all, they did best my boys by outpacing their production output.” He winked at her.

“Thank you for your letter, by the way. I told you my girls could operate the machines and achieve results as good as, or better than, your Ph.D.’s. I have to say, it gave me great pleasure to show up your protégés.”

“And it gave me none to admit that you were right.”

“Fair enough.” They exited Alpha-1. “Do you want to take a peek at Beta-2?” It was the most recently completed of the calutron plants.

“Why not?”

The interior of Beta-2 was painted the same drab light green as the rest of the buildings that comprised Y-12. It had become a running joke around the plant that when people from the outside asked what they manufactured at that big compound twenty minutes outside of Knoxville, the answer most often given was “green paint.”

Beta-2, like the other Beta buildings, housed thirty-six calutrons in a rectangular configuration. The scale of everything was smaller than the Alpha calutrons. But for the cubicle operators, there might as well have been no difference at all.

Nora recognized several of the girls as she and Dr. Lawrence walked the control room floor. They were approximately halfway down the row when Nora spotted her—the fresh-faced girl from today’s orientation. The bright blue uniform accented her tiny waistline.

Heat suffused Nora’s body. Was it hot in here?