For a moment he was silent, thinking.  The searching party had passed on.  They could still hear the purring of the motor as Maenck’s car moved slowly up the street.

“This is a driveway,” murmured Barney.  “People who build driveways into their grounds usually have something to drive.  Whatever it is it should be at the other end of the driveway.  Let’s see if it will carry two.”

Still in the shadow of the hedge they moved cautiously toward the upper end of the private road until presently they saw a building looming in their path.

“A garage?” whispered Barney.

“Or a barn,” suggested the princess.

“In either event it should contain something that can go,” returned the American.  “Let us hope that it can go like—­like—­ah—­the wind.”

“And carry two,” supplemented the princess.

“Wait here,” said Barney.  “If I get caught, run.  Whatever happens you mustn’t be caught.”

Princess Emma dropped back close to the hedge and Barney approached the building, which proved to be a private garage.  The doors were locked, as also were the three windows.  Barney passed entirely around the structure halting at last upon the darkest side.  Here was a window.  Barney tried to loosen the catch with the blade of his pocket knife, but it wouldn’t unfasten.  His endeavors resulted only in snapping short the blade of his knife.  For a moment he stood contemplating the baffling window.  He dared not break the glass for fear of arousing the inmates of the house which, though he could not see it, might be close at hand.

Presently he recalled a scene he had witnessed on State Street in Chicago several years before—­a crowd standing before the window of a jeweler’s shop inspecting a neat little hole that a thief had cut in the glass with a diamond and through which he had inserted his hand and brought forth several hundred dollars worth of loot.  But Barney Custer wore no diamond—­he would as soon have worn a celluloid collar.  But women wore diamonds.  Doubtless the Princess Emma had one.  He ran quickly to her side.

“Have you a diamond ring?” he whispered.

“Gracious!” she exclaimed, “you are progressing rapidly,” and slipped a solitaire from her finger to his hand.

“Thanks,” said Barney.  “I need the practice; but wait and you’ll see that a diamond may be infinitely more valuable than even the broker claims,” and he was gone again into the shadows of the garage.  Here upon the window pane he scratched a rough deep circle, close to the catch.  A quick blow sent the glass clattering to the floor within.  For a minute Barney stood listening for any sign that the noise had attracted attention, but hearing nothing he ran his hand through the hole that he had made and unlatched the frame.  A moment later he had crawled within.

Before him, in the darkness, stood a roadster.  He ran his hand over the pedals and levers, breathing a sigh of relief as his touch revealed the familiar control of a standard make.  Then he went to the double doors.  They opened easily and silently.