heals' analogy had been applied to a spaceship. The ship, operated by
remote control, was filled with pure radioactives. It hovered over the
leech until, rising to the bait, it had followed. Antaeus had left his
mother, the Earth, and was losing his strength in the air. The operator
was allowing the spaceship to run fast enough to keep out of the leech's
grasp, but close enough to keep it coming.

The spaceship and the leech were on a collision course with the Sun.

"Fine, sir," the operator said. "It's inside the orbit of Mercury now."

"Men," the general said, "I swore to destroy that thing. This isn't
exactly the way I wanted to do it. I figured on a more personal way. But
the important thing is the destruction. You will all witness it.
Destruction is at times a sacred mission. This is such a time. Men, I
feel wonderful."

"Turn the spaceship!" It was Moriarty who had spoken. His face was
white. "Turn the damned thing!"

He shoved his figures at them.

They were easy to read. The growth-rate of the leech. The
energy-consumption rate, estimated. Its speed in space, a constant. The
energy it would receive from the Sun as it approached, an exponential
curve. Its energy-absorption rate, figured in terms of growth, expressed
as a hyped-up discontinuous progression.

The result--

"It'll consume the Sun," Moriarty said, very quietly.

The control room turned into a bedlam. Six of them tried to explain it
to O'Donnell at the same time. Then Moriarty tried, and finally
Allenson.

"Its rate of growth is so great and its speed so slow--and it will get
so much energy--that the leech will be able to consume the Sun by the
time it gets there. Or, at least, to live off it until it can consume
it."

O'Donnell didn't bother to understand. He turned to the operator.

"Turn it," he said.

They all hovered over the radar screen, waiting.

* * * * *

The food turned out of the leech's path and streaked away. Ahead was a
tremendous source, but still a long way off. The leech hesitated.

Its cells, recklessly expending energy, shouted for a decision. The food
slowed, tantalizingly near.

The closer source or the greater?

The leech's body wanted food _now_.

It started after it, away from the Sun.

The Sun would come next.

* * * * *

"Pull it out at right angles to the plane of the Solar System," Allenson
said.

The operator touched the controls.