"Right." "And all protein consists of amino acids. _Every_ natural protein back home is built on levo--left turn--amino acids. Here it is just the opposite, the mirror image of what we know. Every amino acid is dextro--to the right!" "But how can it be different here?" "Johnson, they could ask the same question about us with equal justification--or, rather, equal lack of justification." I was trying to feel my way through the confusion. "Barnes, I know a world could be made of anti-matter but--" "No, no. Anti-matter is a reversal of changes within the atom. These atoms are the same as ours. It's the organization that is different--regular molecules with a different twist." "But why should it have killed him then? We absorb starch and reject cellulose which is closely related. But the body just refuses to accept the cellulose. It doesn't necessarily go ahead and die." "Starch and cellulose are both dextro, old man. This is a more fundamental difference. Maybe the body just throws off some of these compounds too. But there were some--plenty, I suspect--it couldn't throw off." He glanced toward the stiffening corpse, sympathetically. "The poor kid couldn't leave well enough alone." * * * * * Well, we are two universal days out from Newtane and soon we will drop from hyper-drive as we reach the orbit of Pluto. I shouldn't still be feeling as uneasy as I do. I'm sure I shouldn't. We have had five friendly, informative days with the people of a great civilization remarkably like ours, and President Hacker has radioed he understands perfectly that we were not responsible for the tragedy, nobody was. The kid, it seems, wasn't the apple of his eye anyway. Ninety men and one corpse returning to the security of _terra firma_. I should, when all is said and done, be happy with the way most things have worked out. But I am a Chronicler and I know the peculiarly symbolic, seemingly superficial ways in which history manages to repeat itself. It is more than three centuries since the last war on Earth between rightists and leftists. That was a matter of differing concepts of economics and politics. I can't help wondering, though, whether there are not even more fundamental points of eventual conflict in the universe that we have barely discovered. If there are, I'm beginning to suspect they'll still have something to do with the unfathomable difference between Right and Left, a difference that took many lives centuries ago--and may not be through with us yet. End of the Project Gutenberg EBook of World in a Mirror, by Albert Teichner