The thing explodes to death

The tremor was repeated, slightly stronger this time. Something was pounding away in the darkness, a steady, regular sound that seemed to come from everywhere around him. It took him a moment to realize it was his own heart.

"Atta boy," he murmured encouragingly "I know you're around. Here's papa. Y'all come visit."

The floor shook slightly beneath the tractor. He stood, searching the dark areas as well as those lit by the machine's headlights. "Come on. Come shake hands, sucker," he whispered tensely.

The tractor rose several inches. Macready lost his balance and tumbled forward, arms windmilling. He found himself staring into the engine at something that might have been a face.

A claw flashed up at him, splitting the steering wheel but missing his face as he threw himself backward.

He kicked at the accelerator and the tractor bounded ten feet. As it rumbled past the gap in the ceiling he jumped and grabbed the edge of the hole.

Ahead of him the thing's face and arms burst through the metal plating of the engine housing. Reaching claws just missed his legs as he scrambled onto the roof. A frustrated hiss echoed through the room below. Macready steadied himself on the quivering roof. It threatened to collapse any second. He lit the short fuse on the dynamite and tossed it toward the tractor cab.

Half the thing's grotesque body emerged from the opening behind Macready, screeching in fury. Something flexible and tough as a rubber hose whipped out and wrapped itself twice around the pilot's chest, tightening and yanking him backward.

At that instant there was an immense explosion, the leaking hydrogen tanks igniting and sending a white fireball fifty feet into the night sky. Mixed in with the flames were the carbonizing remnants of the thing's body.