"We'll try another and more powerful lens," Allison stated, as he turned back to the postmaster's private office. "By the way, Boyd, have you or any of your men been in the Service more than four years?"

"No, I don't think any of us has. What has that got to do with it?"

"Not a thing in the world, as far as your ability is concerned, but there is one point that every one of you overlooked—because you never heard of it. I'm going to try it out myself now and I'll let you know what develops."

With that Allison turned and sauntered back into Rogers's office.

There, spread upon the desk, was the missing blue print, creased and dusty from disuse.

"First time you ever saw this, eh?" Allison inquired of the postmaster.

"The first time I even knew it was there," admitted that official. "How'd you know where to find it?"

"I didn't—but there's an ironclad rule of the department that plans of this nature are to be kept under lock and key for just such emergencies as this. But I guess your predecessor was too busy to worry you with details."

Rogers grunted. It was an open secret that the postmaster who had preceded him had not been any too friendly to his successor.

Allison did not pursue the subject but spread the plan upon an unoccupied table so that he could examine it with care.