f
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:

The Interplanetary Vessel _Arcturus_ sets out for Mars, with
Breckenridge as chief pilot, carrying on board, besides its
regular crew and some passengers, the famous Dr. Stevens,
designer of space