The engineer saw before him at the top of the stair a small doorway, and beyond it a spiral runway leading upward. The light grillwork gate stood invitingly open. Catching the grill with one hand as he rushed through the door, Shelby sought to slam it shut and latch it. He almost had succeeded, and then a huge hand closed upon the bars. One jerk, and a quick grab with the other immense paw and the strange flight and pursuit would be at an end.
But the jerk was delayed. Shelby fired his last round. It did the monster little harm, even though the distance between the two was but four feet. Nevertheless it caused the armored horror to leap back a step, and the moment thus provided was sufficient.
As Shelby stumbled up the dark spiral he heard the thing below tearing at the closed grill. He knew that it could not delay the thing for long. He had just reached the trapdoor at the top of the long climb, when a muffled ripping crash echoed up dimly from far beneath him. The gate was down!
Feverishly he struggled with the heavy trap. Normally it would not have been difficult for him to lift the rectangle of aluminum alloy; but wounded as he was, forcing his numbing limbs to obey him required almost super-human effort. When he had at last succeeded in hoisting it on its hinges, he could again hear the soft padding of hurrying feet.
The engineer found himself in a large room, one wall of which was curved, conforming to the outer contour of the cylindrical tower. Scattered illumination globes gave a dim light to the place. The room was evidently a storehouse for Hekalu's laboratory supplies. Complex mechanisms stood about, evidently waiting to be installed. There were hundreds of metal drums presumably containing chemicals. There were bolts of heavy fabric and stacks of ingots neatly corded. Set in the ceiling of the chamber were several circular windows through the heavy glass of which bright stars shone. Directly above was the roof, and but a few paces distant, the landing stage!
Escape seemed tantalizingly near, but with sinking heart, Shelby noted that there was no easy means of ascent to the roof. He'd have to try to smash one of those windows. But the monster hurrying up the spiral claimed his immediate attention.
Deeply thankful for the peculiar eccentricities of Martian architecture, he hurriedly proceeded to pile ingots on the closed trapdoor. Each of these ingots weighed well over a hundred and fifty pounds. Fortunately for the wounded Earthman, the distance he had to carry them was only a few feet.