roadster, charging through the streets, the horn shrieking a warning. As they arrived, the bright light had disappeared, but soon they saw it again.
"That's the Black Star," Verbeck said. "I can't figure out how he does it, but I suppose the solution will be simple enough when we learn it."
"I'd like to beat it out of him!" Muggs said.
The police had entered the building, and the chief had ascertained that nothing had happened. As far as they knew, there was nobody in the establishment who did not have a right to be there. But that did not mean that the danger was over.
"I don't like the looks of this!" Verbeck said. "I am inclined to believe that the gang is doing the real work in some other place."
"I've got men every place where there is any quantity of precious stones," the chief said, "and they have orders to send an alarm to headquarters the instant they see or hear anything that seems to be suspicious."
The bright light from the sky had disappeared again. Out in the street there was a series of explosions, and Verbeck and Muggs and the chief rushed to a window, and saw clouds of vapor rising from the pavement.
"He's got some scheme!" the chief declared. "Watch yourselves, you men, and be ready to go into action! More of you go into the vault room and watch there!"
The proprietor was like a maniac, and the chief whirled upon him angrily.
"What's the matter with you?" he demanded. "You don't see any of the crook's gang around
