The mass spectrographer said eventually, “Well, it isn’t tungsten.”

Hallam’s broad and humorless face wrinkled into a harsh smile. “All right. Well tell that to Bright-boy Denison. I want a report and—”

“But wait awhile, Dr. Hallam. I’m telling you it’s not tungsten, but that doesn’t mean I know what it is.”

“What do you mean you don’t know what it is.”

“I mean the results are ridiculous.” The technician thought a while. “Impossible, actually. The charge-mass ratio is all wrong.”

“All wrong in what way?”

“Too high. It just can’t be.”

“Well, then,” said Hallam and, regardless of the motive that was driving him, his next remark set him on the road to the Nobel Prize and, it might even be argued, a deserved one, “get the frequency of its characteristic x-radiation and figure out the charge. Don’t just sit around and talk about something being impossible.”

It was a troubled technician who came into Hallam’s office a few days later.

Hallam ignored the trouble on the other’s face—he was never sensitive—and said, “Did you find—” He then cast a troubled look of his own at Denison, sitting at the desk in his own lab and shut the door. “Did you find the nuclear charge?”

“Yes, but it’s wrong.”

“All right, Tracy. Do it over.”

“I did it over a dozen times. It’s wrong.”

“If you made the measurement, that’s it; Don’t argue with the facts.”

Tracy rubbed his ear and said, “I’ve got to, Doc. If I take the measurements seriously, then what you’ve given me is plutonium-186.”

“Plutonium-186? Plutonium-186?”

“The charge is +94. The mass is 186.”

“But that’s impossible. There’s no such isotope. There can’t be.”