d pretty well figure on large oceans," Arcot said. "The land is
green, and there are plenty of clouds."

Far ahead, a low mass of solid land appeared above the blue of the
horizon. It soon became obvious that it was not a continent they were
approaching, but a large island, stretching hundreds of miles north and
south.

Arcot dropped the ship lower; the mountainous terrain had become so
broken that it would be impossible to detect a city from thirty miles
up.

The green defiles of the great mountains not only provided good
camouflage, but kept any great number of ships from attacking the sides,
where the ray stations were. The cities were certainly located with an
eye for war! Arcot wondered what sort of conflict had lasted so long
that cities were designed for perpetual war. Had they never had peace?

"Look!" Fuller called. "There's another city!" Below them, situated in a
little natural bowl in the mountains, was another of the cone cities.

Wade and Fuller manned the ray projectors again; Arcot dropped the ship
toward the city, one hand on the _reverse_ switch in case the
inhabitants tried to use the magnetic beam again.

At last, they had come quite low. There were no ships in the air, and
no people in sight.

Suddenly, the outside microphone picked up a low, humming sound. A long,
cigar-shaped object was heading toward the ship at high speed. It had
been painted a dark, mottled green, and was nearly invisible against
background of foliage beneath the ship.

"Wade! Catch that on the ray!" Arcot commanded sharply, moving the ship
to one side at the same time. Instantly, the guided missile turned and
kept coming toward them.

Wade triggered the molecular beam, and the missile was suddenly dashing
toward the ground with terrific speed. There was a terrific flash of
flame and a shock wave of concussion. A great hole gaped in the ground.

"They sure know their chemistry," remarked Wade, looking down at the
great hole the explosion had torn in the ground. "That wasn't atomic,
but on the other hand, it wasn't dynamite or TNT, either! I'd like to
know what they use!"

"Personally," said Arcot angrily, "I think that was more or less a
gentle hint to move on!" He didn't like the way they were being
received; he had wanted to meet these people. Of course, the other
planet might be inhabited, but if it wasn't--

"I wonder--" said Morey thoughtfully. "Arcot, those people were
obviously warned against our attack--p