“A target that will end the war, Harvey.”

“Civilians and American POWs?”

“They’ll put POWs in every city. And how many more POWs and dead and wounded will there be after the invasion? How many cities will we conventionally bomb off the map? How many American graves?”

“I didn’t become a physicist to learn how to vaporize Japanese.” Harvey’s voice rose.

“None of us did.” Oppy’s voice became nearly tender. “But you tell a mother of a young soldier who died on the beach of Japan—and there will be many thousands of them—that you had a bomb that could have ended the war and that you chose not to use it. Tell his wife. Tell his children.”

The Geiger counter ticked like a speeded clock. The scaler lights multiplied rapidly now that the two bowls were only eight inches apart. In the shadow between, the ball still glittered, like a note between two cymbals. A chain reaction of one kilogram of plutonium released as much energy as thirty-four million pounds of TNT, Joe had heard. Some percussion.

“The issue is not the weapon, Harvey, but the war. Ending the war and saving us from the hideous slaughter to come.”

The trade-off for that kind of power was an alpha radiation that could destroy first the borrow, then the kidney. Everyone knew that the doctors on the Hill refused any responsibility for the Dragon.

“Eighty-eight percent critical at three inches.” Harvey scanned the rolling graph. “The issue is the future after the war. Two inches, Joe.”

After the war the Army would close its bases in New Mexico, Joe thought. The soldiers would be coming home from Europe and the Pacific, though, and they’d flock to the Casa Mañana.

“Teller had the same fears. I’ll tell you what I told him: that if the issue is the world’s postwar future—and I agree it is—the only way to demonstrate the implausibility of any more war is to use this bomb, to make all mankind a witness. This, finally, will be the war to end all wars. Edward Teller will be with us at Trinity. In fact, I had hoped that you would do the countdown for the test.”

“Eighty-nine,” Harvey read.

The Geiger counter sounded like a bow drawn across a bass string. The lights of the scaler flickered, drawing nervous red dashes.

“One more inch, Joe,” Harvey said.

“After the war there will have to be international control of all nuclear devices, and international cooperation for the peacetime uses of the atom. A sober, frightened world will do that, Harvey. But we will have to take the moral lead. We will share information with our allies.”

“With Russia?” Joe asked.

“Yes, with Russia. Of course,” Oppy said.

“Ninety percent. Half an inch, very slowly.”

The Geiger counter echoed an accelerating, snapping wave of electrons.