There was a big, raftered room, and in the middle of the floor Eddie Dugan was struggling groggily to get up, while behind him stood a white-goateed civilian with a wrench, and in front of him a tough-looking younger man was lifting a rifle. The two Germans saw the gun in Manning's hands and made a tableau as they were. It was broken as the burly one's grip relaxed and his Mauser clattered on the floor. Manning motioned toward the goatee. "Dr. Kahl? Better drop that," he advised in German. The little physicist looked down at his wrench and let it fall with an expression of disgust. Then he glared at Manning and called him a couple of names culled from biology rather than physics. "If your man hadn't caught Wolfgang reloading--As it is, you have interrupted my work at the most crucial point imaginable--a work that might yet save the Reich--" He woke up to the nature of his audience, and finished lamely, "And which is in any case the greatest scientific advance of all time." Dugan got shakily back to his feet, scooped up his dropped Browning, and trained it on Wolfgang. "Is that Kahl?" he inquired sourly. "If I'd known this guy wasn't the one we had to capture, I'd have let him have it when I first got the drop on him." Manning didn't answer. His eyes roved rapidly about the interior, alert against another surprise entrance; but anybody else on the premises was lying pretty low. One, in fact, was doing it just under the window Manning had first fired at. He was no longer a factor. One end of the room was storage space for the overflow of Kahl's electrical equipment. Manning recognized some of the articles there and read the labels on a couple of crates, but they gave him no clue to the Herr Doktor's world-shaking research. The door behind Kahl was ajar on a room that, from what showed, might be his laboratory.... * * * * * They'd taken the required prisoner, and all duty called for now was a short wait until Intelligence took him off their hands. But Manning's curiosity was needled. Kahl wasn't modest about whatever he'd done--but his wrath at the "interruption" was genuine, and there might really be something here. The soldier in Manning fought a brief battle with the student, and lost. "What is this work of yours?" He made his voice authoritatively crisp, over the automatic's steady muzzle. Kahl glanced momentarily toward the open door, then glowered at the American for a long ten seconds. "It is not for barbarian eyes." "So there's something worth seeing--or a booby trap, maybe?" said Manning to himself. Aloud he snapped, "Suppose you show us what's in that room. Ahead of me--no, let Wolfgang go first. Keep him covered, Eddie!"