I nodded, and she went deathly pale. "But don't worry," I said quickly. "It may not be as bad as we think." "What!" she gasped. "Fifteen little boys missing on an alien planet, and it may not be bad? Are you out of your mind?" "If you'll calm down a bit and let me explain." I suggested. Snow leaned back in her chair and folded her arms. "Go ahead," she said resignedly. I told her about my being picked up at work by the Security Agents, of my meeting with Baxter, and of my investigation of _Phobos II_. She listened that far in silence, then could hold back no longer. "But what did you find in those lockers? And what does the takeoff thrust and the dehumidifying system have to do with the boys' disappearance?" I smiled reassuringly at her. "Listen, Snow. Baxter, myself, and probably you, too, have one reaction in common about the boys' vanishment from a ship in space. Our very first word on the subject is an incredulous 'Impossible.' Of course, we're using it in the colloquial sense; that of 'I don't believe it!' But if we take it in its literal sense, we'll be absolutely correct. Such a thing _is_ impossible." Snow opened her mouth, but I shushed her unspoken words with a wave of my hand. "I know, you're about to spout something about magnetic grapples and mid-space boardings, or even about long distance teleporting rays--none of which have as yet, so far as we know, been invented--or some such rot. But what are the arguments against these two solitary possibilities? "As to the first; Anders, the pilot, would surely have noticed another ship in his vicinity. The meteorite warnings would have begun jangling when the ship was still hundreds of miles away. And if it could, somehow, evade the signalling devices, Anders would still have heard the ship make contact. You can't drive up in a spaceship big enough to hold at least fifteen normal-sized boys, besides your own crew, and just not be noticed! "So we come to the second, and only other, possibility: Were the boys kidnapped by some ultrasuper teleportation beam? The answer, of course, is a resounding, 'Hell, no!'" Snow frowned. "Why?" "The thrust, Snow, that's why. If that weight were suddenly removed from the ship--boys of Space Scout age usually run to an average weight of one hundred pounds, or, in this case, a total of about fifteen hundred pounds--if that weight had suddenly become missing, then Anders' fuel consumption, remaining the same but with less mass to thrust, would have made him overshoot Earth. This, however, did not happen. In fact, the gauges in the pilot's compartment plainly show that the ship's mass was, on landing, within a fraction of an ounce of its takeoff mass. Therefore, no mass at all was lost in space except that expended by the consumption of fuel."