Short story. Illustrations by Jack Binder. Part of the Johnny Black Series. Appeared in the collected works [i]The Best of L. Sprague de Camp[/i], published in 1978, reissued in 1986. Appeared in the anthologies [i]Modern Masterpieces of Science Fiction[/i], edited by Sam Moskowitz, published in 1965, reissued in 1974; and [i]Dorway Into Time[/i], edited by Sam Moskowitz, published in 1966, reissued in 1974.