"Hmmm, looks like we've contacted a new race. Let's return the call, Lieutenant." A tiny red light glowed beneath a miniature camera on Heselton's desk and almost at once the alien's face registered obvious satisfaction. It waved a six-fingered hand in an unorthodox, but friendly, greeting. Heselton waved back. The alien then pointed to his mouth, made several clacking-grunting sounds, and moved a hand on his desk. The scene switched to another alien standing in front of what looked like a blackboard, with a piece of chalk in his hand. The meaning was clear. "Lieutenant, have this transmission switched to the linguistics section. Maybe those guys can work some sort of language." The screen blanked out. Heselton leaned back, tense, obviously worried. Hesitantly, he reached out and touched a button on the intercom. "Astronomy." "Professor, there's a ship right next door somewhere that should stand out like King Kong in a kindergarten." "I know, Admiral. I've been listening to the intercom. Our optical equipment isn't designed for close range work, but we've been doing the best we can, tried everything from infra-red through ultra-violet. If there is a ship out there I'm afraid it's invisible." Beads of sweat sprinkled Heselton's forehead. "This is bad, Rogers. Mighty bad." Nervously, he walked across to the right of the bridge and stood, hands clasped behind his back, staring blankly out at blackness and the scattered stars. "I know there is a ship out there, and I know that a ship simply can't be invisible, not to radar _and_ optics." "What makes you sure there is only one, sir?" Heselton cracked his fists together. "My God, Rogers, you're right! There might be ..." The intercom clacked. "This is fire control again, sir. I think we've got something on the radiation detectors." "Good work, what did you find?" "Slight radioactivity, typical of interstellar drive mechanisms, somewhere off to our right. Can't tell exactly where, though." "How far away is it?" "I don't know, sir." Heselton's hands dropped to his sides. "Thanks," he said, "for the help." His desk tv flashed into life with a picture of the smiling alien commander. "This is the linguistics section, Admiral. The aliens understand a fairly common galactic symbology, I believe we can translate simple messages for you now." "Ask him where the hell he is," Heselton snapped without thinking, then instantly regretted it as the alien's face showed unmistakable surprise. The alien's smile grew into an almost unbelievable grin. He turned sideways to speak to someone out of sight of the camera and suddenly burst into a series of roaring cackles. "He's laughing, sir." The translator commented unnecessarily. The joke was strictly with the aliens. Heselton's face whitened in quick realization. "Rogers! They _didn't know_ that we can't see them!"