that problem was settled when _Homo
sapiens_ exterminated _Homo neanderthalis_. It appeared that the same
situation had arisen in space. There were humans, and there were Plumies.
Both had interstellar ships. To humans, the fact was alarming. The need
for knowledge, and the danger that Plumies might know more first, and
thereby be able to exterminate humanity, was appalling.

Therefore the _Niccola_. She drove on sunward. She had left one frozen
outer planet far behind. She had crossed the orbits of three others. The
last of these was a gas giant with innumerable moonlets revolving about
it. It was now some thirty millions of miles back and twenty to one side.
The sun, ahead, flared and flamed in emptiness against that expanse of
tinted stars.

Jon Baird worked steadily in the _Niccola's_ radar room. He was one of
those who hoped that the Plumies would not prove to be the natural
enemies of mankind. Now, it looked like this ship wouldn't find out in
this solar system. There were plenty of other ships on the hunt. From
here on, it looked like routine to the next unvisited family of planets.
But meanwhile he worked. Opposite him, Diane Holt worked as steadily, her
dark head bent intently over a radar graph in formation. The immediate
job was the completion of a map of the meteor swarms following cometary
orbits about this sun. They interlaced emptiness with hazards to
navigation, and nobody would try to drive through a solar system without
such a map.

Elsewhere in the ship, everything was normal. The engine room was a place
of stillness and peace, save for the almost inaudible hum of the drive,
running at half a million Gauss flux-density. The skipper did whatever
skippers do when they are invisible to their subordinates. The weapons
officer, Taine, thought appropriate thoughts. In the navigation room the
second officer conscientiously glanced at each separate instrument at
least once in each five minutes, and then carefully surveyed all the
screens showing space outside the ship. The stewards disposed of the
debris of the last meal, and began to get ready for the next. In the
crew's quarters, those off duty read or worked at scrimshaw, or simply
and contentedly loafed.

Diane handed over the transparent radar graph, to be fitted into the
three-dimensional map in the making.

"There's a lump of stuff here," she said interestedly. "It could be the
comet that once followed this orbit, now so old it's lost all its gase