rts of horrible events impending.

I told the girls all I knew of the approaching wanderer. The density
was similar to that of Earth. The oncoming velocity and the calculated
elements of its orbit now were such that within a few weeks more the
new planet would round our Sun and presumably head outward again. It
would pass within a few million miles of us, causing a disturbance to
Earth's orbit, even a change of the inclination of our axis, affecting
our tides and our climate.

"So I've heard," Venza interrupted me. "They say that, and then they
stop. Why can't a newscaster tell you what is so mysterious?"

"For a very good reason, Venza: because you can't throw people into a
panic. This whole thing, up to today, has been withheld from the
public of Earth and Venus. The Martian Union tried to withhold it, but
could not. Every heliogram between the worlds is censored."

"And still," said Venza sarcastically, "you don't tell us what is so
mysterious about this wanderer."

"For one thing," I said, "it changes its direction. No normal heavenly
body does that. They calculated the elements of its orbit last April.
They've done it twenty times since, and every time the projected orbit
is different. Just a little at first, but last week the accursed thing
actually took a sudden turn, as though it were a spaceship."

The girls stared at me. "What does that mean?" Anita asked.

"They're beginning to make wild guesses but we won't go into that."

"What else is mysterious?" Venza demanded.

"The thing isn't normally visible."

Venza shifted her silk-sheathed legs. "Don't talk in code!"

"Not normally visible," I repeated. "A world one-fifth as large as the
Moon could be seen plainly by our 'scopes when well beyond Pluto. It's
now between Jupiter and Mars, invisible to the naked eye, of course,
but still it's not very far away. I've been out there myself. With
instruments, we ought to be able to see its surface; see whether it
has land and water, inhabitants perhaps. You should be able to
distinguish an object on its surface as large as a city, but you
can't."

"Why not?" asked Anita. "Are the clouds too thick? What causes it?"

"They don't even know that," I retorted. "There is something abnormal
about the light-waves coming from it. Not exactly blurred, but a
distortion, a fading. It's some abnormality of the light-waves."

A swift rapping on our door-grid interrupted me, and Snap Dean burst
in.

"Hola-lo, everybo