"It was too late now. Look—see there! We are directly over the Silver Palace! What a beautiful——"
The professor's words were interrupted by a frightful rumbling roar that came up from the gulf surrounding the plateau on which the palace stood. All the way around that gulf a sheet of flame seemed to leap upward through smoke, and then, paralyzed, helpless, hypnotized by the spectacle, they saw the plateau and the palace sink and disappear into the blackness of a great void. Then, like a black funeral pall, the smoke rolled up about them and shut off their view.
But they knew that never again would the eyes of any human being behold the marvelous Silver Palace of the Sierra Madre Mountains.
When the balloon had ascended higher another current of air was encountered, and the course changed. Away they floated over the mountain peaks and out beyond the great range.
At last they came down, made a safe landing, and, to their satisfaction, found themselves within a mile of Huejugilla el Alto.
They had escaped the most frightful perils, but Professor Scotch's heart lay like lead in his bosom, and Hans Dunnerwust was not to be comforted, for they had left Frank Merriwell to his doom.
In Huejugilla el Alto they remained four days, neither of them seeming to have energy enough to do anything.
And, on the fourth day, Frank, Al Bushnell, and two others rode into town and stopped at the hotel.
Picture the meeting between Frank and his friends! Hans shed nearly a bucketful of joyful tears, and Professor Scotch actually swooned from sheer amazement and delight. When the professor recovered, he clung to Frank's hands, saying:
"This is the happiest moment of my life—if I am not dreaming! Frank, my dear boy, I never expected to see you again. How did you escape?"