"When the country of the Garlands comes into view, watch for my light. You will see it--a thin, steady white beam, pointing at the moon. Occasionally I shall send a red flash along its length--at alternating intervals according to the inclosed code. Thus there can be no mistake--I fear treachery--one fears everything in such times as these we are undergoing here! "When you are convinced that it is my light you see, descend toward its source. At an altitude of ten thousand feet, cross into my beam and hold there for a time, that I may see and recognize you. I will send two swift red flashes. Leave the beam at once, and come back into it. I will know then for certain that it is you. "Descend now, down the beam to its source. When I extinguish it, you will see my glow of lights at your landing field. Descend there, and land. "I caution you again. Take everything very slowly! You will be seated, you three, in the lower compartment. When you land--when once you are upon solid ground--extinguish all but one very small light. Then begin to open your door. "I say, _begin_ to open it! It is to be opened very, very slowly. You, Frederick, understood, no doubt, that its queer construction was to some purpose. I was very specific about that! "You are to undo its inner fastenings, and revolve its main circular knob, a few turns at intervals of no less than five minutes each. I want you to take fully thirty minutes to open the door. "Let the new air of Xenephrene in slowly, that you may grow accustomed to it gradually as it comes upon you. This, of course, you have guessed as my reason for such caution. But it is not only the changed air you will be admitting! Other things will come in as well! To them also, you must become accustomed gradually. "When the door is nearly ready to open wide, extinguish your remaining light. Sit quiet! Do not attempt to move about! Let Frederick then join you, when he has flung wide the door. Sit quiet, all three of you. Do not be afraid! There is nothing to fear! It will be strange at first. "I will give you a minute or so to gather your composure. Then I will come in to you--oh, I pray now as I close, that this may all transpire as I have outlined! God grant that you will come safely to me at last, over such a distance! I will be waiting so anxiously for that first sight of you in my beacon beam! "Your affectionate father." * * * * * My voice trembled and broke as I ended. Emotion swept me; not only an answering love for my father which sprang to meet his dear affection as it came from the written words, but a fear as well. And an awe--what was this into which we were plunging that he should be constrained to caution us in such a fashion?