Mattern made it quite clear at the outset that _his_ boys were the Really Important members of the expedition, and that we were simply ballast. In a way, we had to agree. Tension was mounting once again on our sadly disunited planet; there was no telling when the Other Hemisphere would rouse from its quiescence of a hundred years and decide to plunge once more into space. If anything of military value lay out here, we knew we had to find it before They did. The good old armaments race. Hi-ho! The old space stories used to talk about expeditions from Earth. Well, we _were_ from Earth, abstractly speaking--but in actuality we were from America, period. Global unity was as much of a pipedream as it had been three hundred years earlier, in the remote and primitive chemical-rocket era of space travel. Amen. End of sermon. We got to work. * * * * * The planet had no name, and we didn't give it one; a special commission of what was laughably termed the United Nations Organization was working on the problem of assigning names to the hundreds of worlds of the galaxy, using the old idea of borrowing from ancient Terran mythologies in analogy to the Mercury-Venus-Mars nomenclature of our own system. Probably they would end up saddling this world with something like Thoth or Bel-Marduk or perhaps Avalokitesvara. We knew it simply as Planet Four of the system belonging to a yellow-white F5 IV Procyonoid sun, Revised HD Catalog #170861. It was roughly Earthtype, with a diameter of 6100 miles, a gravity index of .93, a mean temperature of 45 degrees F. with a daily fluctuation range of about ten degrees, and a thin, nasty atmosphere composed mostly of carbon dioxide with wisps of helium and nitrogen and the barest smidgeon of oxygen. Quite possibly the air had been breathable by humanoid life a million years ago--but that was a million years ago. We took good care to practice our breathing-mask drills before we ventured out of the ship. The sun, as noted, was an F5 IV and fairly hot, but Planet Four was a hundred eighty-five million miles away from it at perihelion and a good deal farther when it was at the other swing of its rather eccentric orbit; the good old Keplerian ellipse took quite a bit of punishment in this system. Planet Four reminded me in many ways of Mars--except that Mars, of course, had never known intelligent life of any kind, at least none that had troubled to leave a hint of its existence, while this planet had obviously had a flourishing civilization at a time when Pithecanthropus was Earth's noblest being. * * * * *