"But that's impossible. There's no such isotope. There can't be."
"That's what I'm saying to you. But those are the measurements."
"But a situation like that leaves the nucleus over fifty neutrons short. You can't have plutonium-186. You couldn't squeeze ninety-four protons into one nucleus with only ninety-two neutrons and expect it to hang together for even a trillion-trillionth of a second."
"That's what I'm telling you, Doc," said Tracy, patiently.
And then Hallam stopped to think. It was tungsten he was missing and one of its isotopes, tungsten-186, was stable. Tungsten-186 had 74 protons and 112 neutrons in its nucleus. Could something have turned twenty neutrons into twenty protons? Surely that was impossible.
"Are there any signs of radioactivity?" asked Hallam, groping somehow for a road out of the maze.
"I thought of that," said the technician. "It's stable. Absolutely stable."
"Then it can't be plutonium-186."
"I keep telling you, Doc."
Hallam said, hopelessly, "Well, give me the stuff." Alone once more, he sat and looked at the bottle in stupefaction. The most nearly stable isotope of plutonium was plutonium-240, where 146 neutrons were needed to make the 94 protons stick together with some semblance of partial stability.
What could he do now? It was beyond him and he was sorry he had started. After all, he had real work begging to be done, and this thing - this mystery - had nothing to do with him. Tracy had made some stupid mistake or the mass spectrometer was out of whack, or - Well, what of it? Forget the whole thing! Except that Hallam couldn't do that. Sooner or later, Denison would be bound to stop by and, with that irritating half-smile of his, ask after the tungsten. Then what could Hallam say? Could he say, "It isn't tungsten, just as I told you."
Surely Denison would ask, "Oh, and what is it, then?" and nothing imaginable could have made Hallam expose himself to the kind of derision that would follow any claim that it was plutonium-186. He had to find out what it was, and he had to do it himself. Clearly, he couldn't trust anyone.
So about two weeks later he entered Tracy's laboratory in what can fairly be described as a first-class fury.
"Hey, didn't you tell me that stuff was non-radioactive?"
"What stuff?" said Tracy automatically, before he remembered.
"That stuff you called plutonium-186," said Hallam.
"Oh. Well it was stable."
"About as stable as your mental state. If you call this non-radioactive, you belong in a plumber's shop."
Tracy frowned. "Okay, Doc. Pass it over and let's try." And then he said, "Beats me! It is radioactive. Not much, but it is. I don't see how I could have missed that."
"And how far can I trust your crap about plutonium-186?"
The matter had Hallam by the throat now. The mystery had become so exasperating as to be a personal affront Whoever had switched bottles, or switched contents, must either have switched again or have devised a metal for the specific purpose of making a fool of him. In either case, he was ready to pull the world apart to solve the matter if he had to - and if he could.
He had his stubbornness, and an intensity that could not easily be brushed aside, and he went straight to G.C. Kantrowitsch, who was then in the final year of his own rather remarkable career. Kantrowitsch's aid was difficult to enlist but, once enlisted, it quickly caught fire.
Two days later, in fact, he was storming into Hallam's office in a blaze of excitement. "Have you been handling this thing with your hands?"
"Not much," said Hallam.
"Well, don't If you've got any mere, don't. It's emitting positrons."
"Oh?"
"The most energetic positrons I've ever seen . . . And your figures on its radioactivity are too low."
"Too low?"
"Distinctly. And what bothers me is that every measurement I take is just a trifle higher than the one before."
Bronowski came across an apple in the capacious pocket of his jacket and bit into it. "Okay, you've seen Hallam and been kicked out as expected. What next?"
"I haven't quite decided. But whatever it is, it's going to dump him on his fat behind. I saw him once before, you know; years ago, when I first came here; when I thought he was a great man. A great man - He's the greatest villain in the history of science. He's rewritten the history of the Pump, you know, rewritten it here - " Lamont