ens, no moleculars!" snapped Arcot into the transmitter. He was
not their leader, but they saw his wisdom, and the squadron commander
repeated the advice as an order. In the meantime, another ship had
fallen. The dome had its screen up, allowing the multitudes of hidden
stations outside to fight for it.

"Hmm--something to remember when terrestrians have to retire to forts.
They will, too, before this war is over. That way the main fort doesn't
have to lower its ray screen to fight," commented Arcot. He was watching
intensely as a tiny ship swung away from one of the larger machines, and
a tremendously powerful molecular started biting at the fort's ray
screen. The ship seemed nothing but a flying ray projector, which was
what it was.

As they had hoped, the deadly new ray stabbed out from somewhere on the
side of the fort. It was not within the fort.

"Which means," pointed out Morey, "that they can't make stuff to stand
that. Probably the projector would be vulnerable."

But a barrage of heat rays which immediately followed had no apparent
effect. The little radio-controlled molecular beam projector lay on the
rock under the melted ice, blazing incandescent with the rapidly
released energy of the relux.

"Now to try the real test we came here for," Morey clambered back to the
power room, and turned on the controls of the magnetic beam. The ship
was aligned, and then he threw the last switch. The great mass of the
machine jerked violently, and plunged forward as the beam attracted the
magnetic core of the Earth.

Morey could not see it, but almost instantly the shimmer of the
molecular screen on the fort died out. The deadly ray sprang out from
the Thessian projector--and went dead. Frantically the Thessians tried
weapon after weapon, and found them dead almost as soon as they were
turned on--which was the natural result in the terrific magnetic field.

And these men had iron bones, their very bones were attracted by the
beam; they plunged upward toward the ship as the beam touched them, but,
accustomed to the enormous gravitation accelerations of an enormous
world, most of them were not killed.

"Ah--!" exclaimed Arcot. He picked up the transmitter and spoke again to
the Squadron Commander. "Squadron Commander Tharnton, what relux
thickness does your ship carry?"

"Inch and a quarter," replied the surprised voice of the commander.

"Any of the other ships carry heavier?"

"Yes, the special solar investiga