“Final shield under attack!”

On the VR, the PEM authorization programming was now being consumed. Black, penetrating lines engulfed the final protective shield and began forcing their way toward its core.

Prowling hackers were now appearing from all over the world. The number was doubling almost every minute. Before long, anyone with a computer—foreign spies, radicals, terrorists—would have access to all of the U.S. government’s classified information.

As technicians tried vainly to sever power, the assembly on the podium studied the message. Even David and the two NSA agents were trying to crack the code from their van in Spain.

PRIME DIFFERENCE BETWEEN ELEMENTS RESPONSIBLE FORHIROSHIMA AND NAGASAKI

Soshi thought aloud. “The elements responsible for Hiroshima and Nagasaki... Pearl Harbor? Hirohito’s refusal to...”

“We need a number,” Jabba repeated, “not political theories. We’re talking mathematics—not history!”

Soshi fell silent.

“How about payloads?” Brinkerhoff offered. “Casualties? Dollars damage?”

“We’re looking for an exact figure,” Susan reminded. “Damage estimates vary.” She stared up at the message. “The elements responsible...”

Three thousand miles away, David Becker’s eyes flew open. “Elements!” he declared. “We’re talking math, not history!”

All heads turned toward the satellite screen.

“Tankado’s playing word games!” Becker spouted. “The word ‘elements’ has multiple meanings!”

“Spit it out, Mr. Becker,” Fontaine snapped.

“He’s talking about chemical elements—not sociopolitical ones!”

Becker’s announcement met blank looks.

“Elements!” he prompted. “The periodic table! Chemical elements! Didn’t any of you see the movie Fat Man and Little Boy—about the Manhattan Project? The two atomic bombs were different. They used different fuel—different elements!”

Soshi clapped her hands. “Yes! He’s right! I read that! The two bombs used different fuels! One used uranium and one used plutonium! Two different elements!”

A hush swept across the room.

“Uranium and plutonium!” Jabba exclaimed, suddenly hopeful. “The clue asks for the difference between the two elements!” He spun to his army of workers. “The difference between uranium and plutonium! Who knows what it is?”

Blank stares all around.

“Come on!” Jabba said. “Didn’t you kids go to college? Somebody! Anybody! I need the difference between plutonium and uranium!”

No response.

Susan turned to Soshi. “I need access to the Web. Is there a browser here?”

Soshi nodded. “Netscape’s sweetest.”

Susan grabbed her hand. “Come on. We’re going surfing.”