Connor said, "The others--they'll be wondering what happened to their boy. He was alone on that job, we're sure of that. When they hear he's in prison, they'll surely try to contact him--you." "What makes you so sure they will?" "Because," Connor said slowly, "they have to. This is a secret operation. They must prevent our finding out who our prisoner is, finding out that he's from outside Earth." His voice became raw-edged. "They're a threat, Birrel. Wherever they came from, they're danger. Perhaps the worst danger that ever threatened us. We have to find them. You have to help." He did not ask for that help, he commanded it. And with a feeling of unreality, Birrel knew that he could not disobey that command. Connor rose. "You'll stay here, while we set this up. It'll take weeks, working every minute, to get you ready." Weeks later, wearing another man's face, Birrel sat solitary in an isolated cell of a New York prison. He sat there unbelievingly waiting for the impossible, for the secret ones from the wider cosmos. He did not have to wait long. CHAPTER III They came at ten minutes before midnight. Birrel had been sitting in this cell for some twenty hours. The cell was deep in a jail in downtown Manhattan. It was a solitary cell, for a solitary and important prisoner. He had a different face now, a dead man's face. The clothing he wore had belonged to that man. He could speak that man's language, to a certain extent. He was not Ross Birrel, he was a man from Someplace-else. "_What's my name, on that other world?_" Birrel wondered. "_I'm impersonating somebody and don't know who, or what, he was--_" Except that the man he impersonated had been a spy. Secret agent of an unguessable, distant world, ferreting out Earth's defense secrets. A wave of cold disbelief swept Birrel. It was still too fantastic, too incredible. The scientists were wrong about that body, they must be wrong. Connor was wrong. But Connor remained grimly convinced. Before his men took Birrel to the prison, he had said, "They've lost an agent, those people from outside. A valuable man with valuable information. They'll contact you, somehow when our newspaper story appears." "In a locked cell in prison?" Birrel had said, incredulously. "How can they?" "I've an idea," Connor had said, "that they can do quite a lot of things we can't. But we'll be ready for them. The prison guards aren't in on our set-up, of course. But we'll be in the building, watching." He had added, "You may not fool them long. But try. Remember, the important thing is to get them to lead you to the others, to the center of this thing, to their base, wherever it is. We'll follow." That had been twenty hours ago. And now Birrel sat in the cold, stone-walled little cell, and stared at the blank steel door, and told himself that he was a fool, and that Connor was mad. No one could reach him here, even if anybody tried.