Festinger and his collaborators, Henry Riecken and Stanley Schachter, examined conditions under which disconfirmation of beliefs leads to increased conviction in such beliefs in the 1956 book "When Prophecy Fails". The group studied a small apocalyptic cult led by Dorothy Martin (under the pseudonym Marian Keech in the book), a suburban housewife. Martin claimed to have received messages from "the Guardians," a group of superior beings from another planet called 'Clarion.' The messages purportedly said that a flood spreading to form an inland sea stretching from the Arctic Circle to the Gulf of Mexico would destroy the world on December 21, 1954. The three psychologists and several more assistants joined the group. The team observed the group firsthand for months before and after the predicted apocalypse. Many of the group members quit their jobs and disposed of their possessions in preparation for the apocalypse. When doomsday came and went, Martin claimed that the world had been spared because of the "force of Good and light" that the group members had spread. Rather than abandoning their discredited beliefs, group members adhered to them even more strongly and began proselytizing with fervor.