"We trust that this demonstration you have just observed will help you to remember that while seeing may be believing, it's wise not to believe until it has been established just what you saw." * * * * * In his private office, Dr. Clayton leaned forward over his desk. Or, to be more exact, something that looked like Dr. Clayton leaned over the desk. The face was impassive as marble, but, from out a slit in his chest, a pair of black antennae-like feelers were vibrating into a framed picture on the wall, from which the picture had been slid aside. _"Landing safely effected. Brief panic when several Terrestrials sighted ships; all clear now. Full report, containing details on latest successful persuasion of Earthlings that Martians or other aliens are imaginary, will follow."_ From the speaker beneath the desk came sounds of gasps, heavy breathing, then shuffling footsteps. Clayton pushed the picture back into place, then took off the skin-painted vest he wore, with the flat box on its inside. He snapped a switch on the side of his desk. "There; now they can't hear--if any are still hanging around." Professor Elton looked at him bewilderedly. "I don't get it. After all the risk we went to, to convince the public that there ain't no ghosts--as the old saying goes--you arrange to have students hear you going into a 'report to the home planet' act. And you use a code they all know. What's the point in undoing it?" Clayton nodded. "It looks somewhat mad, doesn't it? Well ... the Psychology Team was sure of the necessity. You see, more and more humans remain unconvinced each time one of these hoaxes are exposed. The unconvinced are sure that something fiendish is going on beneath the surface, that the authorities--all kinds from civil to scientific--are engaged in a vast cover-up. We can't prevent this belief; we don't know how to keep it from spreading. So--the alternative is to direct it." Elton nodded slowly. "I can see possibilities along that line--but just what direction was this supposed to kind of bring about?" "Why, obviously, if large-scale invasion from Mars is imminent--and this is the belief that we're all catering to--then it follows that the invasion hasn't already taken place. The two of us, and Harvey Gale, will disappear shortly in one way or another, and gradually public cries for effective planetary defense will mount. "You know who will direct the defense." Transcriber's Note: This etext was produced from _Future Science Fiction_ No. 30 1956. Extensive research did not uncover any evidence that the U.S. copyright on this publication was renewed. Minor spelling and typographical errors have been corrected without note.