Social scientists, in a remarkable experiment, have applied themselves to the following question: What is the reaction, in a group or an individual, to the disconfirmation of a firmly held belief in which there is a substantial investment of self? The experiment, or study, conducted dealt with a group, led by a physician and his wife who came to believe that Salt Lake City would be flooded and themselves spirited to safety by space men taxi-ing them on flying saucers. The actual date of the flood was predicted and all necessary preparations for flight carefully made. The authors succeeded in ""planting"" among the group two observers who attended the seances, hysterical phenomena and constant discussion and planning of the group. They heard the communications relayed from the Creator; they were present when a prank was played by visitors posing as space men; they watched how newsmen and broadcasters were faced and answered; they noted especially how the group accepted and rededicated itself with each disconfirmation. The report, fascinating for all its inside disclosures, offers little by way of conclusions or insights into group behavior. The sociologist will want to have it for reference until other findings enlarge the meaning of this study.