This time I addressed myself to Hanson. "Congratulations, Skipper," I said. "Now you're _three_ grampaws. If Diane keeps _this_ up, you'll be able to man a whole cruiser." The Old Man's face was fiery. "Now, hold everything!" he stormed. "This is goin' too far! Diane don't have to overdo it, just because we're not there! There's such a thing as--_Triplets_! I won't allow it!" "What's the matter," I grinned at him, "afraid of the Three Little Biggs, Skipper. Don't be a big bad wolf!" But even _I_ didn't think it was funny when, at that moment, Joe Marlowe's familiar tones rolled through the room _again_. "Lieutenant Lancelot Biggs," he called, "aboard the _Saturn_--congratulations! You are the father of a fine baby boy--" "Gosh!" I gulped. "This is turning into a parade!" Cap Hanson's face was a study in technicolor. His jowls were dangling to his third weskit button. But oddly enough, at this third dire pronouncement, Lancelot Biggs did not even wince. Instead, his eyes brightened; he rose from the chair into which, a moment before, he had tumbled. "No!" he yelled. "Not a parade--a solution!" "Huh?" I gaped at him. "Solution to what? The unemployment problem?" "No, Sparks! All our troubles! Quadruplets? No! Triplets? No! Twins? No, not even that! Just one baby!" "Y-you mean," I asked him, "that's a repeat message? But, Lanse, you know as well as I do Joe would have announced it as a repeat--" "Certainly. But what we're hearing is the same message over and over again!" "Huh!" Hanson forced the query, new hope in every wrinkle of his brow. "Yes. Remember how Marlowe's orders got grooved before, Sparks? Well, this is some more of the same thing! I know _why_, too. And I _also_ know why we've been having so much trouble with the Themisites!" "Y-you do? Why?" "The moon! The invisible moon--that's the answer! Tell me, Sparks--what sort of things are invisible?" "Why?" I stammered, "dark things seen against a dark background ... light things seen against a light background ... objects marked with protective coloration...." "And _transparent_ things!" chortled Biggs. "Transparent things with just sufficient mass to cause refraction of light! That's what Themis' moon is made of! Pure, unadulterated galena in its natural form is a colorless, transparent substance, sufficiently opaque to occult Themis, but also with enough mass to refract normal light rays! And galena is--" "I get it!" I hollered. "A natural wave-trap for radio transmission. Back in the early days of the Twentieth Century, galena was the substance used in the manufacture of experimental so-called 'crystal sets'!" "By golly, you're right, Lanse! That satellite is large enough to capture and retain a record of Joe Marlowe's voice, and as it revolves it keeps re-transmitting it to us over and over again--" "Lieutenant Lancelot Biggs," repeated the voice of Marlowe--"aboard the _Saturn_--congratulations! You are the father of a fine baby boy!"