Into the Fourth Dimension by Ray Cummings

I said to Brutar, "You asked my help. But you have let me do nothing to help you -- and you explain nothing, so that I have no idea what is going on. Am I not enough your friend by now?"

Brutar smiled; I think he was fatuous enough to believe that he had won me over.

"You will be able to help me, Rob. We're going to place these weapons everywhere. There is a statue near here somewhere -- a giant figure rising from water. I want you to lead us to it. Later -- when we have finished with this great house."

"Weapons? " I echoed. "What sort of weapons?"

He continued to smile. "You called them bricks a while ago. That's what they are -- inert material we brought with us. I had devised other things, but thought that these would suffice. Come here -- I'll show you."

He took one of the bricks. As I stood with him to examine it, a score of the ghostly troopers came across the Subway tracks and fronted us.

It was a light substance, but quite ponderable. Solid, yet rather of the consistency of soft rubber; I seemed to be able to mould its shape slightly with my fingers. Blue-green of color or silver phosphorescence; and it glowed and shimmered in my hands.

I gave it back to Brutar. "You're going to place these -- where?"

"Everywhere," he said. "You shall see. Let us go watch my men place them up there in the great house. This fellow is very bold! He doesn't seem afraid of me!"

He strode vigorously at the intent and curious soldier -- passed through him; but the soldier did not move.

"Come, Rob -- let's go up and watch them."

We moved under the Woolworth Building, up to and through the bottoms of its great elevator shafts. And climbing -- upon what I cannot say or guess -- we passed upward and into the building. Through its walls; its skeleton framework of steel; floating back and forth through its many storied offices. Roaming ghosts!

The ten ghosts of Brutar were floating silently about. We ourselves could be seen by those within the building -- seen as spectres hovering, moving with what silent, sinister purpose they did not know.

Yet they tried to resist us. We came, for instance, upon one of Brutar's men, with the brick still in his hand.

"Shall I place it here? " he asked. "We have chosen this side -- I thought this might be a good spot."

We were some four stories above ground. Before us was one of the great upright girders of the structure.

"I should think so," Brutar agreed.

The man held the glowing, oblong brick within the shadowy steel. He released it, and it floated gently downward -- wafted down like a feather very slowly. But it kept within the outlines of the girder.

"You'd better follow it," said Brutar. "It will stop presently -- and perhaps where you want it."

Inside the building the Earth-people had seen us -- we three hovering there. Men and soldiers were running from room to room, and up and down the staircases trying to get near us. There was a room and a portion of a hallway close to where we now hovered. They were soon thronged with men, crowding against the walls, within which our white shapes were visible. But the walls, solid to them, stopped their advance. They stood regarding us; and now I could see fear upon their faces as their glances followed the downward floating brick. And as it descended a story, many of them rushed down, scrambling against the walls, striving to reach into the place where they saw it.