That is a year ago, now. Ellen and I are married. Soon we shall go back to El Tigre, to see the Doctor and Bill. Dr. Vernon is working on a new model of his tube, and is making a painstaking examination of the strange ship we brought back to earth. Did the destruction of a single city destroy the menace? In all that world above the air, larger than our own, may there not be other cities, or nations and races, perhaps, of intelligent beings? What might we not gain from them in the arts of peace, or not lose to them in war? This summer the four of us are going to adventure above the air again, in that captured ship--to explore the Second Shell. The End.