"Keep them covered, Grim," Hilary said sharply. "I'll take care of this fellow personally."

He walked straight across the room for the Cor, eyes blazing, index finger on trigger. The Cor, fear staring out of his lidless eyes, backed slowly away from the approaching death. There was a hushed silence.

"I'll tell, I'll tell!" the Cor screamed, as the relentless weapon almost touched his paunchy stomach.

"I thought you would," Hilary said grimly, not for an instant relaxing the pressure against the trigger. "If you value your worthless hide, you'd better talk, and talk fast. What switch reverses the machine, to bring on rain? If you are wise, you won't try to fool me."

The wretch almost stumbled in his eagerness. "By the gray soil of Mercury I'll tell you the truth." His arm flung up, pointing. "That k.n.o.b over there controls the--"

Hilary never heard the rest. There was a crash at the other end of the laboratory. One of the Mercutians, tired of keeping his arms high extended, had attempted to rest his huge bulk against a laboratory table. It went over with a splintering crash of gla.s.sware.

Hilary whirled around to face the noise. As he did so, the Cor seized his opportunity. His right arm dropped to his side, jerked up his sun-tube. Hilary heard Grim's warning cry, tried to pivot back again.

But Grim beat him to it. The dynol pistol exploded sharply; the flaming pellet caught the Cor square in his side. There was a dull explosion and the Cor was torn violently into bits. He dropped, a ma.s.s of shapeless blobs.

But now h.e.l.l had broken loose. The Mercutians were not cowards. At the moment of the diversion, every one of them had gone for his sun-tube.

A flame streaked close to Hilary's head, shivered the opposite wall into molten fragments. He ducked behind a table and fired. A Mercutian threw up his hands, staggered and pitched forward heavily. Grim's dynol bullets whined in their pa.s.sage, spattered the laboratory with flying blobs of flesh. They did terrible execution. Hilary's automatic spat its leaden hail.

But the Mercutians were entrenched now behind tables, machinery, whatever cover they could find. The beams from half a dozen sun-tubes slithered across the room, burning flaming paths through the overheated air, bringing the very walls down about them. It could not last long. Already Hilary had a nasty burn across one shoulder; there was a streak of red across Grim's forehead as he hid behind the panel of the entrance, whipping his pistol around to fire, and ducking back again. There were too many of the enemy, and overwhelming reinforcements could be expected any moment. The Earthmen's position was desperate.

Through it all the great weather machine hummed and crackled; the tubes were sheets of surging flame. Hilary cursed softly. If only the Cor had completed his sentence before he died. Hilary would have chanced a sudden rush forward to reverse it, to bring on a deluge of rain and clouds, even though it meant certain death. The machine seemed to gleam at him mockingly; the hum continued with tantalizing smoothness.

"Look out," Grim's voice came to him sharply. He jerked his head back, just in time. A ray streaked past his ear like a thunderbolt. The heat from it scorched his face.

The Mercutians were stealthily crawling nearer, pushing heavy, tables in front of them as shields. He was almost outflanked now. In another minute he would be exposed.

Hilary thought rapidly. His position was untenable. He would have to run for it. A sudden dash to the door might possibly win through. But the machine! He set his teeth hard. If he could not change the weather, at least he could destroy the infernal thing, stop its grinding out perfect sunshine for the Mercutians.

He lifted his weapon. Off to one side a Mercutian arm advanced cautiously, bringing up a sun-tube. He swung on it and fired. The sun-tube clattered to the floor and the arm jerked back, accompanied by a howl of anguish. Hilary smiled grimly, took careful aim at the metal sphere of the machine. The bullet leaped true for its mark. A little round hole showed--but nothing happened. The infernal machine hummed softly as ever.

He cursed, fired again. Another round hole, and that was all. With increasing viciousness he turned his aim on the quartz tubes, pierced them through and through. Before his very eyes, the quartz seemed to run and melt around the holes, to seal them tight as if he had never shot. The blue flames leaped and surged mockingly. The Mercutians were jeering now; raucous calls went up.

Hilary felt a sinking despair. He had failed; would have to run for it now. Small chance to make it, too. Then he heard Grim's deep ba.s.s.

"Hold it a moment," he said as if he had read his thoughts.

Fascinated, Hilary saw the giant's pistol slowly thrust its long barrel around the edge of the crystal slide. A half dozen rays leaped viciously, for it. But a flaming pellet streaked out of its orifice before it was jerked back.

Hilary could see its red path as it struck the sphere of the machine.

The next instant there was a dull explosion and the whole machine disintegrated into a smother of flying fragments. The expanding dynol had done the trick where lead had failed. There would be no more weather control.

But Hilary did not pause to see the finish. Even as the machine burst, he was running across the room, bending low. Fragments whizzed by him at a fearful clip; rays crisscrossed all about him.

But somehow he was through. Grim's finger was on the slide b.u.t.ton. It closed with a snap behind him, cutting off the pursuing howls of rage.

Silently the two men darted up the ramp to the pent-apartment, dashed into the master bedroom. The Mercutian guard whom they had left securely bound, was gone. The Earthmen looked at each other, a great fear in their eyes. In one bound Hilary was at the door slide, thrusting it open. He tore out upon the open terrace, Grim right behind him.

They looked wildly about. The terrace was empty. There was no sign of the _Vagabond_, or of Joan and Wat. High overhead hovered a great burnished diskoid. Long streamlined Mercutian fliers darted through the air, but nowhere was there a sign of the familiar sphere.

Hilary gripped his companion's arm. "They've been captured, Grim," he choked.

"Nonsense," the giant said gruffly, to hide his own misgivings. "They just took alarm at something and winged off."

"But where is the guard then?"

Grim shook his head. He could not answer that. Despair overwhelmed Hilary. After all he had gone through, to have Joan s.n.a.t.c.hed away from him at the moment of success. It was terrible. Wat too, that freckled-faced bantam.

"I should never have left them alone," he accused himself remorsefully.

"Here," said Grim sharply, "none of that. You did exactly the proper thing. We'll find them yet."

It was a confidence that he did not feel. There was the noise of padding feet up the ramp. The Mercutians were coming, in force.

Grim gripped Hilary by the shoulder, shook him vigorously. "They're coming. We're trapped."

Grendon snapped out of the lethargy into which he had sunk, face drawn and gray.

"No. There is a way. Follow me."

The first of the Mercutians pounded heavily into the room when Hilary had thrust Grim into the secret lift. He whirled and fired. The Mercutian coughed and fell forward. Other gray warty faces, furious, thrust from behind their dying comrade. But Hilary was in the lift, pressing the b.u.t.ton for full speed down. A darting ray showered them with rounded smoking bits of vita-crystal, but they were dropping headlong through the building.

Ten minutes later they emerged cautiously from the entrance to the Pullman Building. It was deserted, deathly still. The two Earthmen stopped short, horror-struck at what they saw.

The streets were shambles. Hundreds of bodies lay sprawled in tumbling twisted heaps. Earthmen all, with here and there the grotesque huge bulk of a Mercutian who had failed to hear the warning signal. The bodies were scorched, blackened. Raw agony appeared on contorted desperate faces. It was not good to look upon.

"Wh--what has happened?" Grim gasped, his breath coming heavily.

"Just a little pleasantry of the Mercutians," Hilary said bitterly. He looked upward. High overhead hovered a gigantic shape, motionless.

Its great disk, burnished and dazzling in the cloudless sky, seemed to cast a sinister shadow over the city it had destroyed a second time.

"There's the toy that did it," said Hilary. "I felt the heat while I was a captive up in the Robbins Building. You must have flown over after, and missed it."

Grim shook a great brawny fist aloft. His deceptively mild eyes were hard flames now. His face was set in great strong ridges. Hilary had never seen him this way before.

"I'll rip every Mercutian to pieces with my bare hands--shred him into little bits." He meant it too. Hilary shuddered.

Far off down the wide thoroughfare came the glint of weapons, the sight of ma.s.sed ranks. A Mercutian patrol was shambling along, heavy-gaited.

"Come on, Grim, let's get out of here," said Hilary.