causes are self-obvious facts of existence."

"No, they're not," Jason insisted. "Consider for a second. When you are
away for any length of time from this planet, you must take a refresher
course. To see how things have changed for the worse while you were
gone. Well, that's a linear progression. If things get worse when you
extend into the future, then they have to get better if you extend into
the past. It is also good theory--though I don't know if the facts will
bear me out--to say that if you extend it far enough into the past you
will reach a time when mankind and Pyrrus were not at war with each
other."

Kerk was beyond speech now, only capable of sitting and listening while
Jason drove home the blows of inescapable logic.

"There is evidence to support this theory. Even you will admit that I,
if I am no match for Pyrran life, am surely well versed in it. And all
Pyrran flora and fauna I've seen have one thing in common. They're not
functional. _None_ of their immense armory of weapons is used against
each other. Their toxins don't seem to operate against Pyrran life. They
are good only for dispensing death to Homo sapiens. And _that_ is a
physical impossibility. In the three hundred years that men have been on
this planet, the life forms couldn't have naturally adapted in this
manner."

"But they _have_ done it!" Kerk bellowed.

"You are so right," Jason told him calmly. "And if they have done it
there must be some agency at work. Operating how--I have no idea. But
something has caused the life on Pyrrus to declare war, and I'd like to
find out what that something is. What was the dominant life form here
when your ancestors landed?"

[Illustration]

"I'm sure I wouldn't know," Kerk said. "You're not suggesting, are you,
that there are sentient beings on Pyrrus other than those of human
descent? Creatures who are organizing the planet to battle us?"

"I'm not suggesting it--you are. That means you're getting the idea. I
have no idea what caused this change, but I would sure like to find out.
Then see if it can be changed back. Nothing promised, of course. You'll
agree, though, that it is worth investigating."

* * * * *

Fist smacking into his palm, his heavy footsteps shaking the building,
Kerk paced back and forth the length of the room. He was at war with
himself. New ideas fought old beliefs. It was so sudden--and so hard not
to believe.

Without asking permission