"However," the scientist said slowly, "it's rather a difficult step to
accept the idea that such a parasitical life form could live in _any_
host--even one from another planet and with a totally strange organism,
such as man."
"But it is conceivable," I said doggedly, unable to relinquish the
blossoming hope.
"Perhaps. We know so little of life, of the living organism. We know,
or at least we think we know, that any highly developed being would
have cells, and that it would be constructed ultimately of the same
limited number of atoms from which everything in our universe is
manufactured. But the forms which life could take are infinite. And the
possibility which you suggest has one interesting facet." He paused and
I leaned forward, feeling sweat on my palms. "An intelligent parasite,"
Dr. Temple said thoughtfully, "controlling and living within its host,
feeding upon its host or upon what the host consumed, is one form of
life which could easily survive space travel--providing its host could
survive. For the parasite's own environment within the host would not
substantially be altered."
He glanced at me sharply, as if a sudden thought had occurred to him.
"But why wouldn't such an intelligent being, its mental capacities
presumably far beyond man's if your experience is any indication, have
mastered space travel long before us? Why should it be dependent upon
an inferior intelligence?"
"Because it didn't have a host like man to use," I said quickly.
"That seems to be one main reason for coming here--and for wanting
to bring other aliens here. They've never known a physical organism
like man. They haven't developed one themselves because they didn't
need to--or possibly because it wouldn't have been able to exist under
Martian conditions of life. Their hosts never developed the perfection
of usefulness man's body has reached with his arms and hands and
fingers. What's more, we know that Mars is almost a dead planet.
Wouldn't a parasite eagerly seize upon any new organism that came
along--especially one that was physically far superior to anything that
had evolved on Mars?"
Dr. Temple nodded slowly. "Yes, that is a plausible explanation." He
sighed. "It's all possible, Mr. Cameron, all plausible--up to a point.
The existence of extra-sensory powers in such an intelligence would be
quite natural--even inevitable. But--"
There was reluctance in his voice, compassion in his eyes. "Go on," I
said harshly.
"There are two objections to your theory for which I can find no
answer. One is that my own studies do not reveal any evidence of the
kind of creature you have postulated. And I am led irrevocably to the
conclusion that there would be tell-tale signs."
"And the other?" I whispered.
"The second objection is the manner in which this parasite actually
came to earth--on a returning space ship. This we have from the aliens,
themselves, according to what you overheard. This is the only way they
could have got to earth. And yet that way is impossible."
I didn't want to ask why. The word was thick and hard and painful in my
throat but I had to voice it. "Why? Why?"
"Your alien said something about transferring to another body--and you
concluded that he meant this was necessary for the return trip through
space to Mars. What is especially pertinent, he wanted to effect this
transfer at the last possible moment when it would be too late for any
close physical examination."
"Yes, one of them said something like that."
"And obviously, Mr. Cameron, we do not need the alien to give us the
information that they would want to avoid close examination of the
host. The presence of a powerful parasitical organism in man's body can
quite readily be detected. We might not know what it was but we would
know that it was there. We must assume that this would be particularly
true in the case of a parasite so powerful that it was able to control
directly the human body and mind. Any exhaustive examination would
reveal the alien's existence in the body."