"Old Perk" was the first to recover from his surprise.
"Get the hell out of this neighborhood," he yelled to his working forces. "All of you get down to my office!"
The working force dissolved and "Old Perk" drove away.
At "Old Perk's" office shortly afterward a conference of the defeated forces of the law and of science was held.
"Old Perk" stormed and raged and the detective captain in charge fumed and fussed, but nothing came of it all. One was as powerless as another. Finally the conference adjourned.
The next morning in the mail, Perkins Ferguson, president of Schefert Engineering Corporation, received a letter carefully printed in rubber type. It read:
Thanks for the $50 bill. You cheated us by $99,950. This will never do. Don't be like that. You poor fools, you make us increase our demand. We double it. Leave $200,000 for us on your desk and leave the desk unlocked. We will get it. Every time you ignore one of our demands, one of your number will die. Better take this matter seriously. Last warning.
Invisible Death.
"Not another dime will they get out of me," mused Ferguson.
He started opening the rest of his mail.
A clerk entered and handed him a telegram. It read: