were free to move once more, and I turned to face the instrument
board. Our relative velocity had become practically zero; that is, we
were traveling through space at about the same speed and in the same
direction as the earth. The professor and Hart were consulting a pencil
chart and excitedly looking first through the forward ports and then
into the screen of the periscope.

"This is the approximate location," averred the professor.

"But they are not here," replied Hart.

George and I peered in all directions and could see nothing excepting
the marvels of the universe we had been viewing. The moon now seemed
very close and its craters and so-called seas were as plainly visible as
in a four-inch telescope on earth. But we saw nothing of the enemy.

The earth was a huge ball still, but much smaller than when I had first
observed it from the heavens. The sun's corona--the flaming streamers
which the professor declared extended as much as five million miles into
space--was partly hidden behind the rim of the earth and the effect was
blinding. A thin crescent of brilliant light marked the rim of our
planet and the rest was in shadow, but a shadow that was lighted
awesomely in cold green by reflected light from her satellite.

"I have it!" suddenly shouted the professor. "We are all in very nearly
the same line with reference to the sun, and the enemy is between the
blazing body and ourselves. We must shift our position, move into the
shadow of the earth. We have missed our calculation by a few hundred
miles, that is all."

All! I thought. These astronomers, so accustomed to dealing in
tremendous distances that must be measured in light-years, thought
nothing of an error of several hundred miles. But I suppose it was
really an inconsiderable amount, at that.

At any rate, we shifted position and looked around a bit more. We saw
nothing at first. Then Hart consulted the chronometer.

"Time is up!" he shouted.

* * * * *

On the instant there was a flash of dazzling green light from a point
not a hundred miles from our position, a flash that was followed by a
streaking pencil of the same light shooting earthward with terrific
velocity. Breathlessly we followed its length, saw it burst like a bomb
and hurl three green balls from itself which sped at equally spaced
angles to form a perfect triangle. They hovered a moment at about two
thousand miles above the surface of the earth, accor