John Carter has summoned the local sheriff to a site where he claims saucers have landed, not once but several times. Each time, the saucers are gone when the sheriff finally arrives. Now David Vincent has come, lured by Carter's claim that he can predict the time of the next landing. When Carter's prediction proves true, he and David Vincent manage to commandeer the saucer - at last, proof of the invasion! But one alien escapes to warn his people. And further complications arise from a couple fleeing the country, whose plane the saucer inadvertently downed