ns. The Nigrans thought it was some kind of destruction ray. That
had started the terrible destructive war of the Black Star.

"Let's just hang here peaceably and see what they do," Arcot suggested.

Motionless, the _Ancient Mariner_ hung before the advancing attack of
the great battle fleet. The shining hull was a thing of beauty in the
golden sunlight as it waited for the advancing ships.

The alien ships slowed as they approached and spread out in a great
fan-shaped crescent.

Suddenly, the _Ancient Mariner_ gave a tremendous leap and hurtled
toward them at a terrific speed, under an acceleration so great that
Arcot was nearly hurled into unconsciousness. He would have been except
for the terrific mass of the ship. To produce that acceleration in so
great a mass, a tremendous force was needed, a force that even made the
enemy fleet reel under its blow!

But, sudden as it was, Arcot had managed to push the power into reverse,
using the force of the molecular drive to counteract the attraction the
aliens had brought to bear.

The whole mighty fabric of the ship creaked as the titanic load came
upon it. They were using a force of a million tons!

The mighty lux beams withstood the stress, however, and the ship came to
a halt, then was swiftly backing away from the alien battle fleet.

"We can give them all they want!" said Arcot grimly. He noticed that
Wade and Fuller had been knocked out by the sudden blow, but Morey,
though slightly groggy, was still in possession of his senses.

"Let's not," Morey remonstrated. "We may be able to make friends with
them, but not if we kill them off."

"Right!" replied Arcot, "but we're going to give them a little
demonstration of power!"

The _Ancient Mariner_ leaped suddenly upward with a speed that defied
the eyes of the men at the rays of the enemy ships. Then, as they turned
to follow the sudden motion of the ship--_it was not there!_

The _Ancient Mariner_ had vanished!

Morey was startled for an instant as the ship and his companions
disappeared around him, then he realized what had happened. Arcot had
used the invisibility apparatus!

Arcot turned and raced swiftly far off to one side, behind the strange
ships, and hovered over the great cliff that made the edge of the cleft
that was the river bed. Then he snapped the ship into full visibility.

Wade and Fuller had recovered by now, and Arcot started barking out
orders. "Wade--Fuller--take the molecular ray, Wa