When the sentry faced the captain again, he stared into the mouth of a service pistol.

"Sorry," said the officer, "but I've got to get inside." Captain Taylor turned to Masters. "Keep him covered. I'll be back unless the bomb goes off."

"The bomb," whispered Norden, fearfully, "should have exploded. I was double-crossed. They sent me here to get caught! The dirty—"

"Watch Norden, and you might keep your eye on Funky, here," Taylor said, pointing to the slobbering man who had dropped to his knees at the sight of the orange sphere. "I'm going inside."

The captain moved through the gate. The silence was uncanny. Since the war began this factory had never been idle. Thousands of cannon made; contracts for countless more! But now quiet, save for an undescribable, whispering overtone that seemed to permeate the air.

Something glowed in the semi-darkness ahead like a pile of hot ashes on the ground.

Taylor entered the long forge room. A white hot splinter of metal hung from the crane. There were a dozen heaps of the glowing ashes scattered about the room, but no sign of life.

He moved on into the finishing room, where the long tubes of howitzers and field pieces lay in various stages of construction. Still there was silence.

The whispering grew louder, like a breeze stirring dry cornstalks.

The silence suddenly was broken by a scream. Then another. There was a sound of running footsteps.

Taylor dropped behind a lathe.

Through the door came an orange glow. Sharply outlined against the eerie light ran a human figure, a man in overalls, carrying a hammer. On the fellow's face was frozen fear. He halted, turned and looked behind him.

The darkness vanished as through the doorway floated a huge, orange sphere of light.

"Stop! Go back! I mean you no harm!" screamed the workman.

The ball of orange fire floated on toward him. The man's arm raised. He hurled the hammer straight at the sphere.

The missile rang, bounced back and fell to the sandy floor.

A small flicker of flame wafted over the surface of the sphere. Then it lashed out like a whip toward the trembling man. His entire body glowed like a torch, then crumpled to the floor in a heap of ashes.

Scarcely daring to breathe, the captain watched the sphere float over the ashes of its victim for a moment; then, apparently satisfied that the man no longer lived, floated back through the doorway.

Taylor took a deep breath. It might be well if the bomb would explode, but he knew now it had been silenced.

In an insulated panel on the wall were the remains of an electric switchboard. The copper switches were fused, the wires burned through. The huge cables that brought the electric current to the switchboard lay molten on the floor.

The bomb probably was electrical and undoubtedly had been fused like the switchboard.

The captain had one objective now, to get out of the plant before the orange spheres discovered him. He didn't know what he faced, but something told him that it had never faced mankind before. He had no weapon to combat the sphere.

Taylor reached the forge room again. He stepped over more glowing piles of ashes.

Then his ears caught a crescendo of the whispering that he had heard before. He looked behind him. In the doorway was an orange glow. The sphere was coming—looking for him!

Behind the forge was a machine which had been used to operate the crane. Beyond it was stygian darkness. He might hide there.

The captain slipped toward the machine. Every bit of electrical wiring on the controls had been fused.

The room grew lighter, the whispering louder and then, through the doorway, floated the dazzling sphere.

Something gripped Taylor's shoulder muscles. A mild electrical shock coursed through his body, as if an invisible feeler had passed over him.

The sphere halted, changed its direction and floated slowly toward the captain.

Instinctively, Taylor backed into the corner behind the machine. He dropped to his hands and knees and was free of the invisible feeler! Again the orange sphere halted, as if trying to relocate its victim.

Taylor rounded a pillar which supported the track for the crane. His fingers struck an accumulation of rubbish that had been tossed into the corner. He started to push it out of the way, when the floor beneath it moved. It was a trap door!

A gasp of surprise came from Taylor's lips. He had a chance. But the sound gave him away. The electrical feeler touched him again. The shock jerked at his muscles and the sphere started floating nearer.

The trap door swung back. Taylor's right boot touched the top rung of the ladder. He moved his left boot down to the next rung. Each movement seemed to take ages and every exertion of his muscles was agony as the electrical shock gripped him with increasing intensity.

He forced his body down into the opening. He saw the flame flickering over the surface of the sphere as the thing prepared to strike.

The sphere seemed to pulse briefly as he released his grasp on the rim of the opening and shoved himself downward into the hole. He dropped several feet.

Above him a brilliant flash of fire lit the opening.

The sphere itself hovered above the hole.