The Turber roof was dim with dotted lights. But it was all in operation. Groups of soldiers at intervals; occasionally a transport car passing along on its narrow rails.
The fellow at the gate had waved vaguely toward this viaduct we now were traversing. We had followed his gesture. Our idea was to locate some Turber official whom we might fool—or force—into giving us information about Nanette.
A low metal building showed ahead of us. It was small; it seemed perhaps of only one room. An isolated, dark spread of roof was around it. This viaduct we were on led to it. The little house had open windows, low to the floor, and there was a glow of light within.
I whispered: "Some official may be on duty there. If we can rush him—make him tell us—"
A kiosk leading down into the city showed a hundred feet or so beyond the little building.
We left the viaduct. We crept forward over the dark open roof. We came to one of the open windows of the building. There must have been at that instant a dark figure lurking near us on the roof. Watching us. But we did not see it.
The window stood with its sill at our knees. We dropped low, peered in.
A single metal room with a glow of light. A metal table-block held a strange instrument of tubes and coils. Strange to me; but not to Alan. It was a Time-vision instrument! Its screen stood facing us; upon it was an image of our tower, a phantom speeding tower!
A man sat with his back to us, hunched over the instrument. It was Turber! He was alone in the room. Alan's lips went to my ear: