effect he did not anticipate. The
ion-forming points were of minutely different lengths and patterns, so
the radiation inevitably accompanying the ion clouds was of minutely
varying wave lengths. The consequence of using the two graters was, of
course, that rather astonishing peaks of energy manifested themselves
in ultra-microscopic packages for a considerable distance from the
device. But Lockley did not plan that. It happened because of the
materials he had to use in lieu of something better.

When it was finished he told Jill, "I can only check ion production
here. If it works, it ought to make a lighter-flame flicker when near
the points. If it does that, I'll go up the road to where the
trailer-truck stopped. I've a pretty good idea that the road's blocked
by a terror beam there."

Absorbed, he threw the switch. And instantly there was a racking,
deafening explosion. The pistol on the car seat blew itself to bits,
smashing the windshield and ripping the cushion open. The three
cartridges in its cylinder had exploded simultaneously.

Lockley seized a pitchfork. He stood savagely, ready for anything.
Powder smoke drifted through the barn. Nothing else happened.

After long, tense moments, Lockley said slowly, "That could be another
weapon the monsters have turned on. It's been imagined. They could be
using a broadcast or a beam we haven't suspected to disarm the troops
of the cordon. They could have a detonator beam that sets off
explosives at a distance. It's possible. And if that's what they're
turning on they only have to sweep the sky and the bombers aloft will
be wiped out."

But there were no sounds other than the slowly diminishing drip of
water from the barn roof, and the house eaves, and the few trees in
the barnyard.

"Anyhow they've ruined our only weapon," said Lockley coldly. "It
would be a detonation beam setting off the cartridges. That would be a
perfect protection against atomic bombs, if the chemical explosive
that makes them go off could be triggered from a distance. Clever
people, these monsters!"

Then he said abruptly, "Come on! It's ten times more necessary for us
to get to where somebody can make use of our information!"

"Go where?" asked Jill, shaken once more.

"We take to the woods until dark," said Lockley, "and meanwhile I'll
check this supposedly promising gadget--though it looks pretty feeble
if the monsters have a detonating beam--against the road blocking beam
up yonder.