time _we_ have the luck! The Reds slipped. Oh, how
they slipped!"

Webb watched the major, a thin little smile pulling at his pursed mouth.
"Miracles sometimes do happen," he remarked. "I suppose the sub has a
fix for us."

Kelgarries passed over the flimsy strip of paper he had been waving as a
banner of triumph. Webb read the notation on it and bent over the map,
making a mark with one of those needle-sharp pencils which seemed to
grow in his breast pocket, ready for use. Then he made a second mark.

"Well, it narrows it a bit," he conceded. Ashe looked in turn and
laughed.

"I would like to hear your definition of 'narrow' sometime, Miles.
Remember we have to cover this on foot, and a difference of twenty miles
can mean a lot."

"That mark is quite a bit in from the sea." McNeil offered his own
protest when he saw the marking. "We don't know that country--"

Webb shoved his glasses back for the hundredth time that morning. "I
suppose we could consider this critical, condition red," he said in such
a dubious tone that he might have been begging someone to protest his
statement. But no one did. Millaird was busy with the map.

"I think we do, Miles!" He looked to Ashe. "You'll parachute in. The
packs with which you will be equipped are special stuff. Once you have
them off sprinkle them with a powder Miles will provide and in ten
minutes there won't be enough of them left for anyone to identify. We
haven't but a dozen of these, and we can't throw them away except in a
crisis. Find the base and rig up the detector. Your fix in this time
will be easy--but it is the other end of the line we must have. Until
you locate that, stick to the job. Don't communicate with us until you
have it!"

"There is the possibility," Ashe pointed out, "the Reds may have more
than one intermediate post. They probably have played it smart and set
up a series of them to spoil a direct trace, as each would lead only to
another farther back in time----"

"All right. If that proves true, just get us the next one back,"
Millaird returned. "From that we can trace them along if we must send in
some of the boys wearing dinosaur skins later. We _have_ to find their
primary base, and if that hunt goes the hard way, well, we do it the
hard way."

"How did you get the fix?" McNeil asked.

"One of their field parties ran into trouble and yelled for help."

"Did they get it?"

The major grinned. "What do you think? You know the rules--and