in
space, knowing what would come. Yet, when it came, he was almost
blinded. A blast of light, a light so intense that it was a tangible,
solid thing, roared through the cleft and hurtled Earthward.

Then the bolt was gone and the cleft was closing. The tug of forces was
growing less. He had just seconds left to reach that diminishing crack
in the blackness.

Like a streak of vengeance itself, Case sent his ship across the void.
His lips moved in silent prayer. There were only seconds now. The crack
was growing smaller, and that meant his speed was not great enough. To
risk more power might blow the ship apart. But he had to get through. He
must, he must....

He _was_ through!

* * * * *

Case was through, through the cleft and beyond the thunder. He was
hurtling out of blackness into a world of light. Frantically, he cut
down his speed, not knowing whether he was going into open space or the
side of a mountain, whether in this new world he would be going up or
down.

His altimeter had switched on automatically. That was a relief. A quick
glance showed the dial at 90,000 feet. The retarding jets were slowing
his drop, and Case had time for a look at strange terrain below.

From his present height, it looked like rolling country. There were
hills, valleys, a checkerboard of green and tan that might be cultivated
ground, a river.

But most important of all, there was a city, a city of towers and
pinnacles more impressive than any on Earth. Three of those towers
interested Case. They stood apart, the center tower hundreds of feet
higher than the two which flanked it, and all three were like fingers
pointing directly at the place where the cleft had been.

Case made decisions rapidly. He had to get the ship out of the air
before someone saw it. First, though, he'd have to make sure it would be
air he stepped into when he got out. He had a space suit in the forward
locker, but putting that on would slow him up.

An intake valve hissed away. Soon, there would be something to test.
Then the hissing stopped. That was a good sign. Pressure outside the
ship was almost the same as inside. There was an atmosphere.

But of what was that atmosphere composed? That was now the big question.
Case set the controls and turned to the intake tank. With the turn of a
petcock, there came another hiss. Case got out his cigarette lighter and
flicked it into flame.

He held his breath as the flame w