reddish pigment that protected them.

"Luckily, the military of his nation--the United States, I think they
called it, thought that this pigment might be a useful protective
shield for supplies. Extracts were made and tested before the Blowup
came, and there was quite a bit of it on hand.

"But the real hero of protection was a general named Ardleigh. He
ordered every man and woman in his command inoculated with the extract
right after the Blowup--when communications were disorganized and
commanders of isolated units had unchallengeable power. He was later
found to be insane, but his crazy idea was right. The inoculations
killed ten per cent of his command and turned those who lived a bright
red, but none of the living showed a sign of radiation sickness after
they received the extract.

"By this time your ancestors--the Runners--had gone, and those who
stayed were too busy trying to remain alive to worry much about them.
The "Double A" vaccine--named for Anderson and Ardleigh--was given to
every person and animal that could be reached, but it was only a small
fraction of the population that survived. The others died. But enough
men and animals remained to get a toe-hold on their ruined world, and
they slowly rebuilt.

"We had forgotten about you Runners--but it seems you didn't forget
us. You sealed us off--forced us to remain on Earth. And by the time
we were again ready for space, you were able to prevent us. But we
will not be denied forever. It took an entire planet working together
to get me on Mars to learn your secrets. And when I got here, I found
that I wouldn't have time to learn. We had forgotten one simple
thing--my skin color. It isn't normal here and there is no way of
changing it since the extract combines permanently with body cells. So
I had to do the next best thing--obtain a sample of your technology
and bring it to Earth. I planned at first to get enough money to buy a
ship. But those creeps in Marsport don't lose like gentlemen. I damn
near had to beat my way out of that joint. And when a couple of them
came after me, I figured it was all up. I could kill them of course,
but that wouldn't solve anything. Since I can't fly one of your ships
yet, I couldn't steal one--and I wouldn't have time to buy one because
I was pretty sure the Patrol would be after me as soon as the rumors
of a red man got around. You see--_they_ know what we look like and
its their job to keep us cooped up--"

"Hmm," I