Langford turned and stared soberly at Gurney. "If we wanted to warn them we could send them a little mechanical man, complete in every detail armed with miniature weapons. They've simply sent us a replica of themselves, a model in miniature. It's so unbelievably complex that we could learn nothing by subjecting it to mechanical tests. But we don't have to know what makes it tick.
"They've warned us that they can multiply by fission, so rapidly that they could overrun the Earth in a few hours; they've also warned us that if they find themselves facing impossible odds, they won't hesitate to destroy themselves."
Commander Gurney had returned to his desk and stood facing Langford, his face as grim as death. "I quite agree," he said. "That was—an ugly warning. Langford, letting that ship get away was worse than treasonable. Your twenty minutes are up!"
He was reaching for the communication disk on the far side of his desk when Langford reached inside his uniform for the second time. When the big man withdrew his hand he was clasping an automatic pistol.
Gurney took a swift step backward, his eyes widening in alarm. "So the guards forgot to search you!"
"I'm afraid they did, sir!" Langford said, quietly. "Sit down. I'm going to ask a small favor. A port clearance permit, signed and sealed by you; if you give me your word you won't move until I've cleared the port I won't tie you up."
Gurney sat down and stared at the young space officer in scornful mockery. "Suppose I refuse to promise anything. Would you blast me down in cold blood?"
Langford hesitated. His jaw tightened and a candid defiance came into his stare. "No!" he said.
"Then if you're not prepared to murder me you haven't got what it takes to exact a promise!" Gurney said.
Langford shook his head. "That's sheer sophistry," he pointed out. "I've just laid my cards on the table. If you take advantage of my good faith you'll be hitting below the belt. You see, sir, there's something I've got to do; if I fail I'll come back and give myself up."