"Amen," Berenson said. "I would hate to see true confusion."

"For green badges, there are three levels of clearance. Level one is lowest—no access to designated secret areas. Level two is limited access for duty purposes—the special security guards have level two green badges. Level three is the clearance we share."

"I will be level two," Berenson said.

As they returned to the train, Patricia asked, "Being level two means he won't know exactly what the Stone is?"

"When you get to the seventh chamber, you have to know a lot."

"But not about what's in the libraries."

"No," Lanier said.

That sobered her. Berenson was morose, and he didn't even know about the libraries.

The four spacesuited soldiers ran in long, graceful leaps across the lunar surface with only the stars and a quarter-Earth to light their way. Mirsky watched them from the top of a boulder, only his white helmet showing. In his right hand, he held an electric torch, pointed back toward his team comrades waiting in a gully carved by a rolling rock millions of years before. When the four were in the proper position, he flashed the light on and off three times.

The objective—a mock-up of a lunar settlement bunker—lay a hundred meters beyond the boulder. The four defenders were now by the airlock. Mirsky raised his AKV-297—automatic vacuum-adapted Kalashnikov projectile rifle—and pointed it at the airlock hatch.

The hatch opened and Mirsky raised the rifle slightly, centering it on a cross-barred target near the hatchway signal lights. With one gloved finger, he depressed the side-mounted trigger and felt the rifle kick three times. A thin line of burning gunpowder discharge from the barrel glowed briefly in the darkness. The target blew out in tatters of plastic as the door opened.

Mirsky heard the exercise supervisor read off the numbers of the four space-suited defenders and order them to assume a reclining posture. "Your airlock is also incapacitated," the supervisor added laconically. "Fine work, Lieutenant Colonel. . . You may proceed."

Mirsky and his three comrades advanced toward the mock-up. The defenders lay on the lunar soil outside the open hatchway, motionless except for the advancing numbers of their backpack life support displays. Mirsky leaned over and winked at one of them through his visor. The defender glared back at him, not in the least amused.

"Look over your shoulder at two o'clock, Comrade Lieutenant Colonel," one of his men advised. Mirsky turned around and followed the line of the corporal's thickly protected arm and gloved finger.

The Potato, a sharp point of light with a clearly discernible oblong shape, had just risen above the Moon's horizon.

It seemed that all his life, people had been pointing it out to him—Yefremova three years before, the first among them.

"Yes, I see," Mirsky acknowledged.

"That is why we train, is it not, Comrade Lieutenant Colonel?"

Mirsky didn't answer. The supervisor cut in and demanded they stop the useless chatter.

"The stars have ears, Corporal," Mirsky advised the soldier. "Let's take our objective and get home in time for more political lessons." The corporal met Mirsky's glance and grimaced but said nothing more.