omb on it and leaving."

After a brief discussion, with only perfunctory objections from Clyde
and Oberfield who, as astronomers, wanted to land to take other
readings, the decision was carried.

The _Magellan_ swung up a couple of hundred miles above the Sun-tappers'
plateau. Haines and his crew loaded the bulky H-bomb into the main
launcher in the tail of the ship. Then the _Magellan_ aimed itself at
the target, and the rocket-driven bomb roared out.

Down it sped, zeroing in on the wall of the station. There was a
blinding flash, a glare as brilliant as that of the Sun itself, as it
hit square on the mark. This time Burl watched through carefully
shielded viewscreens. The scene was obscured by a wide-flung cloud of
white--tens of thousands of cubic feet of satellite rock turned
instantaneously into dust particles. After the dust cleared away, they
saw only a gaping crater where the plateau had been--a volcanic hole,
miles wide and glowing red, from which spread vast, deep cracks
throughout the entire visible hemisphere of the moon.

The men on the _Magellan_ were awed and silent. The thought occurred to
each of them, beyond his capacity to deny it: what if this had happened
on Earth?

"Of course," said Ferrati slowly, "the low gravity of Iapetus accounts
for the greater extent of the disaster. If this had been Bikini or...."
But under the glares of the rest of the crew, his sentence trailed off
weakly.

Lockhart turned away from the viewer. "Mr. Oberfield," he said,
unexpectedly formal and official, "you may chart our course for Uranus."

"Aye, aye, sir," said that usually dour personage, with alacrity.

With forced smiles, the rest of the crew drifted away to their duties.
The _Magellan_ pulled away from Saturn, heading out again toward the
limits of the solar system, but it was several days before everyone had
quite managed to dismiss the vision of the H-bomb from his mind.

Chapter 15. _Ice Cold on Oberon_

Nevertheless, from that point on, a different spirit seemed to animate
everyone aboard the _Magellan_. There was the feeling that they had
closed with the enemy and found themselves not wanting. There was the
feeling that they possessed powers not inferior to those of their
unknown enemies. The thought had been haunting them all along that they
were in the position of a backward people facing an advanced
invader--something like the problem of the Aztecs when faced with the
gunpowder and armo