he throat of the old volcano was a pit of blackness in the midst of gray ash and the red-yellow of cinders. Beside it were other flecks of color: red, moving bodies; metal, that twinkled brightly under the desert sun—and in an instant they were gone. Nor did Smithy, throwing the thundering plane close over that place, know how near he had passed to sudden, invisible death. Rugged pinnacles of rock were ahead. The plane under Smithy's hands vaulted over them and roared on above the desert.

"Did you see them?" Smithy was shouting.

The man in the forward cockpit turned to face his pilot. "I am apologizing, Smith, for all the things I have been thinking and haven't said. We've got a job on our hands. Now let's find that fool sheriff who thinks he's hunting for drunken Indians. We must warn him."

Smithy wondered at the wisps of blue smoke still rising from the ruins of Seven Palms as he drove in above it. It seemed years since he had left the Basin, yet the wreckage of this little town, only five miles outside, still smoldered.

Colonel Culver was shouting to him. "East," he said. "Swing east. There's fighting over there." Then, in his usual cool tone: "I'll take the ship, Smith. Give then a burst or two from up here—perhaps the sheriff can use a little help."

Across the yellow sand ran a desert road. Ten miles away black smoke clouds were lifting. Smithy knew there had been a little settlement there. A dozen houses, perhaps, and a gasoline station. At half that distance the clear sunlight showed moving objects on the sand: automobiles, smaller dots that were running them. They came suddenly to sharp visibility as the plane drew near. Tiny bursts of white meant rifle fire.

They were a thousand feet up and close when Smithy saw the first car vanish in flame. Others followed swiftly. Men were falling. A dozen of them had made up the sheriff's posse, and now, like the cars, they, too, burst into flame and either vanished utterly or, like living torches, were cast down upon the sand.

Still no sign of the enemy, more than the ripping stab of green fire from a sand dune at one side. They were over and past before Smithy, looking back, saw the red ones leap out into view.

---

ulver must have seen them in the same instant. He throttled down to a safe banking speed. Opened full, the DeGrosse would have whipped them around in a turn that would have meant instant death. From five miles distant they shot in on a long slant. Smithy's hands were off the stick. It was Culver's ship now.

He saw the man peering through his sights, then the roar of the motor held other, sharper sounds. Thin flames were stabbing through the propeller disk, and he knew that the bow guns were sending messengers on ahead where red figures waited on the sand.

Their trajectory flattened. Culver half rolled the ship as they sped overhead. "He wants a look at them," Smithy was thinking. Then a blast of heat struck him full in the face.

It was Smithy's hand on the stick that righted the ship; only the instant response of the big DeGrosse motor tore them up and away from the sands that were reaching for those wings.

His face was seared, but the pain of it was forgotten in the knowledge that their drunken, twisting flight had whipped out the fire licking back from the forward cockpit. He saw Culver's head, fallen awkwardly to one side. The helmet in one part was charred to a crisp.

He leveled off. He was thinking: "Another man gone! Can't I ever fight back? If I only had a gun!" Then he knew he was looking at the pistol grip, where Colonel Culver's brown hand had brought an awkward weapon to life. His lips twisted to a whimsical smile, though his eyes still held the same cold fury, as he whispered: "And I don't even know that the damn thing's loaded—but I'm going to find out!"

---

hey were clustered on the sands below him as he roared overhead. He was flying at two thousand, the throttle open full. Beside the ship a gun swung its long barrel downward. It sputtered almost soundlessly—but where it passed, the sand rose up in spouting fountains.

But his wild speed made the gunfire almost useless. The shell-bursts were spaced too far apart; they straddled the blot of figures.

He came back at five thousand feet, slowly—until the ship lurched, and he saw the right wing tip vanish in a shower of molten metal. He threw the ship over and away from the invisible beam; the plane writhed and twisted across the last half mile of sky. He was over them when he pulled into a tight spiral, then he swung the pistol grip that controlled the gun until the dot in the crystal was merged with the target of clustering red forms. The gun sputtered.

Below the plane, the quiet desert heaved its smooth surface convulsively into the air. Even above the roar of the motor Smithy heard the terrific thunder of that one long explosion.

Above the rim of the forward cockpit Culver's head rolled uneasily; his voice, thick and uncertain, came back through the phone; and later—only a matter of minutes later, though fifty miles away—Smithy set the plane down on a level expanse of sand and tore frantically at his belt. Colonel Culver was weakly raising his head.

---

hat hit us?" he demanded when Smithy got to him. "Did I crash?" He looked about him with dazed eyes from which he never would have seen again, but for the protection of his goggles.

"Fire," said Smithy tersely. "They did it, the devils, and it wasn't a flame-thrower, either. There wasn't a flash of their cursed green light. It just flicked us for a second. You got the worst of it. Your half roll saved us. That thing, whatever it was, would have ripped our left wing off in a second."

He was looking at the forward cockpit where the metal fuselage was melted. The leather cushioning around the edge was black and charred. Culver's helmet had protected him, but half of his face was seared as if it had been struck by a white flame.

"But we got some of them: they know we can hit back...." Smithy began, but knew he was speaking to deaf ears. Again his passenger had lapsed into unconsciousness.

Quickly he disconnected their own radio receiver and threw on the emergency radio siren. Ahead of them for a hundred miles an invisible beam was carrying the discordant blast. Then, with throttle open full, regardless of levels and of air traffic that tore frenziedly from his path, he drove straight for the home field.

---

n the office of the Governor, the radio newscaster was announcing last-minute items of interest. The Governor switched off the instrument as Smithy entered, supporting the tall figure of Colonel Culver, whose face and head were swathed in bandages. Culver had insisted upon accompanying him for the rendering of their report, though Smithy had to do the talking for both of them.

He outlined their experience in brief sentences. "And now," he was saying grimly, "you can go as far as you please, Governor. You've got a man's sized fight on your hands. We don't know how many there are of them. We don't know how fast they'll spread out, but—"

A shrill wail interrupted him. From the newscasting instrument came a flash of red that filled the room. The crystal, the emergency call, installed on all radios within the past year and never yet used, was clamoring for the country's attention.

Governor Drake sprang to switch it on, and tried to explain to Smithy as he did so. "It's out of my hands now," he said. "Washington has—" Then the radio came on with a voice which shouted:

"Emergency order. All aircraft take notice. Mole-men"—Smithy started at the sound of the word; it was the name he had given them himself—"Mole-men are invading Western states. A new race. They have come from within the earth. In Arizona, three ships of the Transcontinental Day Line, Southern Division, have been destroyed with the loss of all passengers and crew. Shattered in air.

"It is war, war with an unknown race. Goldfield, Nevada, is in ruins. Heavy loss of life. Federal Government taking control. Air-Control Board orders traffic to avoid following areas...."

There followed a list of locations, while still the red crystal blazed its warning across the land and to all aircraft in the skies. Southern California, Arizona, Nevada—Southern Transcontinental Routes closed; all except military aircraft grounded in restricted areas.

---

mithy's excitement had left him. In his mind he was looking far off, deep under the surface of the world. "They've been there," he said quietly, "thousands of years. A new race—and they've just now learned of this other world outside. Three ships downed! They picked them off in the air just as they tried to do with us. I knew we had a fight on our hands."

His voice died to silence in the room where now the new announcer was giving a list of the dead—a room where men were speechless before an emergency no man could have foreseen. But Smithy's eyes, gazing far off, saw nothing of that room. Again he was seated on an outthrust point of rock, Dean Rawson beside him, and from the black depths beneath a man's voice was rising clearly, mockingly it seemed, in song:

"The devil is there to pay," Smithy repeated softly. He leaned across and placed one hand on Colonel Culver's knee. "With your assistance, Colonel, I'd like to go down there and find him. You and I, we know the way—we'll organize an expedition. Maybe we can settle that debt."

---