"Yes."

"Unless this antidote were placed into the river carefully, in some way regulating the flow of the water, then we are faced with a danger of floods. There is a tremendous volume of water built up in the mountains, and the flow is regulated through our facilities here. But we are only able to handle 4,400,000 cubic yards capacity. Anything above that would have disastrous effects."

"I'll notify our people to use it only with the utmost caution when they confiscate the antidote." Illya did not mention the possibility the assault might fail. He didn't even want to ponder that potentiality.

The director nodded. "It will have to be used soon," he said, "before too great a volume of water can build in the mountains."

Using his U.N.C.L.E. communicator, Illya Kuryakin contacted Mr. Waverly in New York and imparted this information. U.N.C.L.E. headquarters was in a state of suspense waiting to learn how the invasion of the fortress was progressing. To that moment, they had received no communication.

For the next two hours Illya sat in the director's office. The continued inactivity was telling on his nerves. Finally, the immobility became too much for him, and he told the director he was going up to the observation deck again, to get some air.

The chill wind seemed to have increased in velocity outside. Illya walked along the observation deck, hands in the pockets of his mackinaw, brooding. He looked down at the frozen floor of salt, thinking how very close THRUSH had come in this single bid for world domination. And it wasn't over yet. If THRUSH had managed to get a large quantity of the salt chemical out of that mountain fortress.

Waverly had told him that the interceptor planes he had sent into the area the night before had encountered nothing. Unless they got it out before, Illya thought. Better give Mr. Waverly another call. Maybe...

In the quiet of the early morning and with the dynamos in the dam beneath him shut down, Illya heard the helicopter before he saw it.

He tilted his head back, ears straining, peering up into the cold, gray sky. He saw it finally, coming in from the west, across Lake Mead, a tiny speck at first, and then looming larger as it approached the dam.

He thought at first that it was an U.N.C.L.E. helicopter, sent by Mr. Waverly for some reason. But as it neared, he saw that it was smaller, a different model than that used by U.N.C.L.E.

THRUSH! Of course! That was why Waverly had wanted him to remain at Hoover Dam; he had suspected that THRUSH might come there to inspect its handiwork.

Illya turned and began to run toward the helicopter that had brought him to Hoover Dam, sitting silently in the empty parking lot at one end of the observation deck. His blood raced. Finally he was going to get a chance to act.

He reached the helicopter. It was empty. Where was that blasted pilot? He looked again at the approaching helicopter. It had reached the far end of the dam, coming over the bluff there.

No time to look for the pilot now, Illya thought. He slid into the cockpit, fastened the safety belt, and switched on the ignition. He let the rotary blades revolve slowly, warming, and stared upward through the glass dome.

They had seen him. The-other helicopter slowed, halting its approach, and then banked sharply, turning, and started back the way it had come. Illya shoved the throttle on the U.N.C.L.E. copter forward, and it rose, gliding left as he hurriedly maneuverd the controls.

His face grim, Illya chased after the helicopter.

THREE

The U.N.C.L.E. attacking force supplemented by interceptor planes and jet fighters overhead, left the mining community of Granite River a few minutes before daybreak.

Napoleon Solo, weak, frost-bitten hands encased in heavy mittens, fatigue covering him like a blanket after a restless night, had arrived a few minutes earlier in a jeep driven by Emmett. Despite loud protestations from the men present, concerned over his appearance, Solo perversely insisted he was leading the attack, no matter what happened.

The force consisted of roughly a hundred men, specially trained in this type of assignment, flown in from various parts of the country. There were several jeeps, three large canvas-covered trucks, and an arsenal ranging from handguns to small mortars.

Mounted on two of the jeeps were strange-looking black boxes, somewhat larger than fruit crates, and containing a multitude of dials and gauges. Both boxes were covertly watched over by skilled U.N.C.L.E. technicians from New York City.

Upon seeing the boxes, Solo knew immediately how Waverly planned to penetrate the concrete and-steel fortress. Each was capable, he knew, of producing a type of Laser beam, specially modified by U.N.C.L.E. scientists. The beam, used only on rare occasions by U.N.C.L.E. because of the awesome destructive power it possessed, was able to disintegrate, according to intensity, any metal or substance known to man.

Napoleon Solo, riding in the lead jeep, led the convoy up the mountain road. They encountered no resistance. When they reached the end of the road leading upward from Granite River, they found a second road, its entrance well hidden, that would deploy into the mountains to the right. This second road had been apparently built by THRUSH, since neither of the forest rangers professed any knowledge of it.

The convoy entered this second road. Overhead, one of the U.N.C.L.E. intercept jets radioed via the short wave band in Solo's jeep that no THRUSH opposition awaited them outside the entrance to the fortress. Solo reasoned that THRUSH had lookouts in the immediate area, and that they knew of U.N.C.L.E.'s pending arrival, and of the jets. Apparently, he decided, THRUSH felt their fortress was impenetrable, and were content to stave off the U.N.C.L.E. attack from within.

They came in sight of the sloping granite wall that hid the entrance to the fortress minutes later. Acting with well-organized speed, the U.N.C.L.E. force began to mobilize. Men dismounted from the trucks and jeeps, weapons were loaded, and the boxes housing the deadly Laser beams were carefully lifted to the ground and placed in readiness.

One of the jets, fighter-equipped, made passes directly overhead, waiting. When the U.N.C.L.E. unit was at attack-ready, Solo turned to where the technicians hovered about the Laser boxes. The mountain road was still and silent. The tension in the chill, snow-tinged air was electric.

Napoleon Solo gave the command. Buttons were pressed simultaneously on the black boxes. They began to glow with a violent purplish light, blinding if looked at directly, and a low, humming sound came from each. The light and the hum lasted only a single instant, and then the boxes became still again.

The lower portion of the granite wall before them, and the concrete-and-steel behind it, disintegrated.

In that single instant the Laser beams were trained on the wall, a gaping hole appeared there almost magically revealing the warehouse Solo had been in the day before It had been jammed with THRUSH guards, waiting there. Those who had been unlucky enough to be directly in front of the entranceway had caught the glancing impact of the Lasers, and lay now on the concrete floor. Some were dead, others terribly burned by the radiation The rest milled about in panic, the suddenness of the assault turning their rank into chaotic confusion.

The U.N.C.L.E. force, led by Solo, attacked under protective cover of a burst of machine gun fire from the jet above, spraying the mountain road in front of the entrance.

They encountered almost no opposition from the frightened THRUSH guards. The element of surprise, and the awesome destructive power of the Lasers, had made the U.N.C.L.E. penetration of the fortress a quick and, for them, bloodless one.