The music, which had been playing softly, suddenly stopped at a wave of Joe’s hand.  He stood for a moment motionless before the veiled figure.

“Her spirit is dissolving into thin air!” he said in a low voice, which, nevertheless, carried to every one in the crowd.

Suddenly Joe took hold of the veil in the center and directly over the outlined head of the figure in the chair.  Quickly the young magician raised the soft, black silk gauze, whisking it quickly to one side.

The audience gasped.

The chair, in which but a moment before Helen Morton had been seated, was empty!  The girl had disappeared—­vanished!  Joe stooped and raised from the stage the newspaper.  It showed not a sign of break or tear.

Then, before the applause could begin, the girl appeared, walking out from one of the improvised wings of the circus stage.  She smiled and bowed.  The act had been a great success.  Now the silent admiration of the throng gave place to a wave of hand clapping and feet stamping.

“Was it all right, Joe?” asked Helen, as he held her hand and they both bowed their appreciation of the applause.

“Couldn’t have been better!” he said.  “We’ll do this trick regularly now.  It takes even better than my ten thousand dollar box mystery.  You were great!”

“I’m so glad!”

The two performers were bowing themselves off the stage when suddenly there came the unmistakable roar of a wild beast from the direction of the animal tent.  It seemed to shake the very ground.  At the same time a voice cried: 

“A tiger is loose!  One of the tigers is out of his cage!”

CHAPTER II

A DANGEROUS SWING

There is no cry which so startles the average circus audience as that which is raised when one of the wild animals is said to be at large.  Not even the alarm that the big tent is falling or is about to be blown over will cause such a panic as the shout: 

“A tiger is loose!”

There is something instinctive, and perfectly natural, in the fear of the wild jungle beasts.  Let it be said that a tiger or a lion is loose, and it causes greater fear, even, than when it is stated that an elephant is on a rampage.  An elephant seems a big, but good-natured, creature; though often they turn ugly.  But a lion or a tiger is always feared when loose.

But the chances are not one in a hundred that a circus lion or a tiger, getting out of its cage, would attack any one.  The creature is so surprised at getting loose, and so frightened at the hue and cry at once raised, that all it wants to do is to slink off and hide, and the only harm it might do would be to some one who tried to stop it from running away.

Joe Strong, Jim Tracy, and the other circus executives and employees knew this as soon as they heard the cry:  “A tiger is loose.”  Who raised the cry and which of the several tigers in the Sampson show was out of its cage, neither Joe nor any of those in the big tent near him knew.  But they realized the emergency, and knew what to do.