From somewhere far to the north, another interceptor rocket had found the atomic warhead of an enemy bomb.

Brittain knew and recognized that flash. He screamed wordlessly and then began to sob like a hysterical child.

Karnes began to slap him again. "Come on, what was it?"

"Don"t--don"t let them go back to New York! It said--it said--" he gasped and took a deep breath "--WE"LL ALL BE KILLED!" he screamed.

"Why?" Karnes"s voice was cold.

"BOMB!" Brittain screamed again.

After a few more minutes of questioning, Karnes finally got the rest of the story from him.

The Galactics had found that on this date a nuclear bomb would get through the UN screen and completely destroy most of Greater New York.

Only one other bomb would get through, but it would be thrown off course and land somewhere in the Pacific, having missed Los Angeles entirely.

"Anything else?" asked Karnes after a few seconds of silence from Brittain. "Didn"t it say they would have to prevent that?"

Brittain"s voice was dull now. "All it said was that the records would have to be preserved. It said that things must go on exactly as before. It said that nothing must interfere with the complete development, whatever that means."

Karnes pushed his way out of the room and back towards the pilot"s compartment. What the pilot had to say was no news to Karnes.

"Radio from New York says that a bomb missed LA and hit the ocean.

That was a close one."

Karnes nodded silently, and leaned back in the stewardess" seat to think.

No wonder Brittain had been so anxious to get out of New York.

New York would be destroyed, but that was inevitable. The thing that had bothered him, his dilemma, was solved.

Was this the real Earth that he lived in, or a museum that had been set up by the Galactics? If it was old Earth, then man would solve his present problems and go on to solve the problem of time travel and interstellar transportation. The present war would be just another little incident in the far past, like the battles of Gettysburg and Agincourt.

And if it were the museum Earth? No difference. For the Galactics had decided not to interfere. They had decided to let the race of Earth go on as it was--exactly as it had gone before. It made no difference, really. _No difference at all._ A perfect duplication of an original _was_ the original, in every meaningful way.

"Funny," said the pilot abruptly, "I"m not getting any signal from New York."

Karnes took a deep breath and bit at his lower lip. But he did not look toward the horror that was New York. The city was gone, but the world was there--solid and real!

_You"d better expand your museum a little bit, boys_, he thought.

_We"ll need to include Mars and Venus before very long. And then the stars._