Manning was all eyes for Kahl's invention; his first impression was that the room was disappointingly small and bare. There was nothing that looked like a rocket motor, a guided missile, or even an improved submarine periscope. But then the American's eyes narrowed as they took in what was there.
There were no windows, and walls, floor and ceiling were metal or sheathed with metal. Around them ran what looked like medium-thick pipes, without openings or discernible use. The only furniture was a table, supporting a rather fantastic electrical setup—stuff in the thousands of megacycles, judging by the heavy dielectric tubes and coils that were just a copper twist or two; that was what Manning had glimpsed from outside.
Then a movement jerked Manning's gaze back to the prisoners—and he almost shot the Herr Doktor. For Kahl had contrived to halt near the apparatus-laden table, had taken one quick step and thrown a switch.
The damage—if damage there was—was already done; that thought stayed Manning's trigger finger. But nothing seemed to have happened; only when the contacts had touched the light had flickered briefly, and something had made a deep humming sound that rose in pitch like an electric motor starting under load—rose and snapped off in an instant.
But something stayed wrong. The unconscious faculty of observation that had been sharpened for Manning in shell-smashed towns where the ability to notice small wrongnesses might keep a man from touching off a hidden mine told him that.... He tried to read the expressions of the two Germans. Every wrinkle on Kahl's face beamed crafty triumph. But his helper's look made Manning blink. Wolfgang's Aryan-blue eyes bulged with panic. And they were staring past Manning, at the door.
Eddie Dugan broke the tense silence. "Ray—where's the light coming from?"
That was it! "Watch them!" rasped Manning, and whirled to face the door.
It was ablaze with green-gold sunlight.
II