They sat in silence, while the field outside became shrouded in night. And they speculated, as best they could from the few facts they had, as to what this might mean to the world, to their country, to themselves. It was an hour before Blake was aware of the fact that he was hungry. He rose to leave, but paused while Colonel Boynton answered the phone. The first startled exclamation held him rigid while he tried to piece together the officer's curt responses and guess at what was being told. "Colonel Boynton 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