arge and thick, the letters S.O.S. appeared in dark green on the
clayey open space. The letters were thirty feet high, and the lines
were five feet wide. They should show distinctly from the air.

"I think," said Lockley with satisfaction, "that we might get
something out of this! If it's sighted, a 'copter might risk coming in
after us." He looked at her appraisingly. "I think you'd enjoy a good
meal."

"I want to say something," said Jill carefully. "I think you've been
trying to cheer me up, after saying something to arouse me--which I
needed. If the creatures aren't monsters, they'll never actually let
anybody loose who's seen that they aren't. Isn't that true? And if it
is--"

"We know of six men who were captured," insisted Lockley, "and I was
one of them. All six escaped. Vale may have escaped. They're not good
at keeping prisoners. We don't know and can't know unless it's
mentioned on a news broadcast that he's out and away. So there's
absolutely no reason to assume that Vale is dead."

"But if he saw them, when he was fighting them--"

"The evidence," insisted Lockley again, "is that he saw monsters. The
only reason to doubt it is that they blindfolded four of us."

Jill seemed to think very hard. Presently she said resolutely, "I'm
going to keep on hoping anyhow!"

"Good girl!" said Lockley.

They waited. He was impatient, both with fate and with himself. He
felt that he'd made Jill face reality when--if this S.O.S. signal
brought help--it wasn't necessary. And there was enough of grimness in
the present situation to make it cruelty.

After a very long time they heard a faint droning in the air. There
might have been others when they were trudging over bad terrain, and
they might not have noticed because they were not listening for such
sounds. There were planes aloft all around the lake area. They'd been
sent up originally in response to a radar warning of something coming
in from space. Now they flew in vast circles around the landing place
of that reported object. They flew high, so high that only contrails
would have pointed them out. But atmospheric conditions today were
such that contrails did not form. The planes were invisible from the
ground.

But the pilots could see. When one patrol group was relieved by
another, it carried high-magnification photographs of all the park, to
be developed and examined with magnifying glasses for any signs of
activity by the crew of the object from space.