it before I suggested their
destruction, and I conferred for a few moments with Forsyth, who's just
about tops in biology and bacteriology. He said that they had by no
means learned as much as they wished to, but they'd been forced to leave
in any event. Remember that pure hydrogen, the atmosphere we were
actually living in while on the ship, is quite as inert as pure
oxygen--when alone. But the two get very rough when mixed together. The
longer those ships lay there the more dangerously explosive they became.
If we hadn't destroyed them, they would have wrecked themselves. I still
think we followed the only logical course.

"Dr. Forsyth mentioned the danger of disease. There's a remote
possibility that we might be susceptible to their germs. I don't believe
we would be, for our chemical constitution is so vastly different. For
instance, the Venerians and Terrestrians can visit each other with
perfect freedom. The Venerians have diseases, and so do we, of course;
but there are things in the blood of Venerians that are absolutely
deadly to any Terrestrian organism. We have a similar deadly effect on
Venerian germs. It isn't immunity--it's simply that our respective
constitutions are so different that we don't need immunity. Similarly,
Forsyth thinks we would be completely resistant to all diseases brought
by the invaders. However, it's safer to remove the danger, if any,
first, and check afterward."

The three men sped rapidly back to New York, flying nearly sixty miles
above the surface of the Earth, where there would be no interfering
traffic, till at length they were above the big city, and dropping
swiftly in a vertical traffic lane.

Shortly thereafter they settled lightly in the landing cradle at the
Arcot Laboratories. Arcot's father, and Morey's, were there, anxiously
awaiting their return. The elder Arcot had for many years held the
reputation of being the nation's greatest physicist, but recently he had
lost it--to his son. Morey Senior was the president and chief
stockholder in the Transcontinental Air Lines. The Arcots, father and
son, had turned all their inventions over to their close friends, the
Moreys. For many years the success of the great air lines had been
dependent in large part on the inventions of the Arcots; these new
discoveries enabled them to keep one step ahead of competition, and as
they also made the huge transport machines for other companies, they
drew tremendous profits from these mec