"Ah, two are humans of a strange breed!" a snarling voice barked from the wall, in the Callistonian language. "Our deductions were accurate, as usual--it is to the humans of Planet Three, whose bodies are a trifle less puny than those of the humanity of the satellites, that we owe our recent reverses. However, those reverses were merely temporary--humanity, no matter what its breed, shall very shortly disappear from the satellites. Now, you scum of the Solar System, you shall be permitted to witness an entrancing spectacle on the way to our headquarters, where all your knowledge is to be taken from you before you die, lingeringly and horribly. There is a strange space-vessel nearing us probably searching for the one we took and which you dogs of Callisto must have been fortunate enough to take from us before we could study and kill its human cargo. Watch its destruction and cringe--and know, in your suffering, that the more you suffer, the greater shall be our enjoyment." "I believe that," King acknowledged. As all three prisoners stared at the wall-screen, upon which was pictured a huge football of scarred grey steel, Czuv was amazed to see the faces of Breckenridge and King light up with fierce smiles of pleasure and anticipation. "You dissemble well," remarked the Callistonian. "That will rob them of much pleasure." "They'll get robbed of more than that," King returned. "This is too good to keep, and since they cannot understand English, I'll tell you something. I told you about Stevens. He apparently wasn't killed, as we thought. He must have escaped, and there is the result. That ship there is far from innocent--her being so far out of range of any of our power-plants proves that. That vessel is the _Sirius_--the research laboratory of the IPC--the Inter-Planetary Corporation! It carries the greatest scientific minds of three of the inner planets, and it is loaded with pure poison or it wouldn't be here. Oh, you hexans, what you have got coming to you!" * * * * * _Concluding a Thrilling New Serial of Interplanetary Life and Travel by Edward E. Smith, Ph.D._ _Author of "Skylark of Space," and "Skylark Three"_ PART III Spacehounds of IPC _The question of rays--their expanding power for good and evil--is receiving increasing attention from scientists. The x-ray has been found to be very beneficial, given in certain quantities, but extremely inimical to health, and even fatal, if too much exposure is given. The powers of the cosmic rays have not been fully discovered as yet. And there is no reason to doubt the theory that there may be found still more destructive and powerful rays. Even wars are becoming a more dangerous plaything for nations of our world--to say nothing of other possible enemies from other parts of our universe. Stevens and Nadia Newton meet with thrilling experiences galore in this concluding instalment._ What Went Before: