speaking.... McGuire?... Yes, Lieutenant.... Over
Mount Lawson?... Yes--yes, the same ship, I've no doubt."

His voice was even and cool in contrast to the excited tones that
carried faintly to Blake standing by.

"Quite right!" he said shortly. "You will remain where you are: act as
observer: hold this line open and keep me informed. Captain Blake will
leave immediately for observation. A squadron will follow. Let me know
promptly what you see."

He turned abruptly to the waiting man.

"It is back!" he said. "We're in luck! Over the observatories at Mount
Lawson; descending, so Lieutenant McGuire says. Take the same ship you
had up to-day. Look them over--get up close--good luck!" He turned
again to the phone.

There were planes rolling from their hangars before Blake could reach
his own ship. Their engines were thundering: men were rushing across
the field, pulling on leather helmets and coats as they ran--all this
while he warmed up his engine.

A mechanic thrust in a package of sandwiches and a thermos of coffee
while he waited. And Captain Blake grinned cheerfully and gulped the
last of his food as he waved to the mechanics to pull out the wheel
blocks. He opened the throttle and shot out into the dark.

He climbed and circled the field, saw the waving motion of lights in
red and green that marked the take-off of the planes of the 91st, and
he straightened out on a course that in less than two hours would
bring him over the heights of Mount Lawson and the mystery that
awaited him there. And he fingered the trigger grip that was part of
the stick and nodded within his dark cockpit at the rattle of a
machine gun that merged its staccato notes with the engine's roar.

But he felt, as he thought of that monster shape, as some primordial
man might have felt, setting forth with a stone in his hand to wage
war on a saurian beast.

CHAPTER IV

If Colonel Boynton could have stood with one of his lieutenants and
Professor Sykes on a mountain top, he would have found, perhaps, the
answer to his question. He had wondered in a puzzled fashion why the
great ship had shown its mysterious presence over the flying field. He
had questioned whether it was indeed the field that had been the
object of their attention or whether in the cloudy murk they had
merely wandered past. Could he have seen with the eyes of Lieutenant
McGuire the descent of the great shape over Mount Lawson, he would
have known beyond doubt that her