Hart Jones pondered the matter and I could see that he was overjoyed at the prospect of getting into the thing in earnest. "About one week," he replied, "providing you can send a force of fifty expert mechanics to my hangar at once and supply all material as fast as I shall require it."

"Excellent," said the Secretary. "We'll have the men there in a few hours and will obtain whatever you need, regardless of cost, for immediate delivery. Incidentally, there will be several scientists as well, who will supervise the installation of two types of ray generators and their projecting mechanisms on the Pioneer. You will need them later."

"I don't doubt we shall," said Hart. "And now, with your permission, we shall leave for the hangar. I'm ready to start work."

"Capital!" Secretary Simler pressed every one of a row of buttons set in his desk top. We were dismissed.

"Well," said I, when we reached the outside, "he has given you quite a job, Hart!"

"You said something," he replied. "But, if this threat from the skies proves as real and as calamitous as I think it will, we all have our work cut out for us."

"Do you really believe this enemy comes from another planet?" asked George as we entered the Pioneer for the trip home.

"Where else can they be from?" countered Hart. "But, really it makes no difference to us now. We have to go after them in earnest. Don't want to quit, do you, George?"

"Wha-a-at?" shouted George, as he jerked savagely at the main switch of the Pioneer. "You know me better than that, Hart. Did I ever let you down in anything?"