The Martians’ probable ignorance of the power of his automatic made it impracticable for Robert to attempt forcing them to open the door again. Then, suddenly, he remembered the tremendous lifting power of the _Sphere_, and a possible solution came to him. Carefully he maneuvered the _Sphere_, raising it slowly to the roof. As he felt the jar of the shell against the rafters he increased the lift. He could hear the building groan with the immense pressure. Then he opened the disk’s surface to its maximum and switched on the current! For a moment the _Sphere_ swayed uncertainly as the stout rafters writhed against the tremendous power of the disk. Robert caught a glimpse of the Martians flattened against the door in consternation. The next instant the _Sphere_ shot upward with a crash as the roof of ths building collapsed behind it! Instantly Robert shut off its lifting power, and began maneuvering the _Sphere_ back downward and toward the palace. * * * * * Fortunately the _Sphere_ seemed undamaged by its unusual exit from the building. Within a minute after his escape Robert had it immediately over the palace gardens where the princess and his companions were to join him. The gardens were dark and forbidding-looking beneath him, though the ruddy orange rim of Phobus already was visible over the horizon’s edge. As yet there was no sign of pursuit. Softly the _Sphere_ settled like a round, dark cloud. As it reached a level of perhaps thirty feet Robert saw a darker blotch on the expanse of lawn in back of the princess’ quarters. Being sufficiently familiar with the garden to know that this was not a part of the shrubbery, he suspected and hoped that it was his friends awaiting him. He dared not show a light yet, but continued to settle as rapidly as was safe. Then, to Robert’s relief, a small, carefully shaded flashlight winked twice at him from below. This was the signal agreed upon. A moment later the _Sphere_ came to rest on the turf. A glance through the windows was sufficient to recognize his friends. Taggert came close and rapped on the glass. His low “Hurry” reached Robert in spite of the double panes. Hurrying down the narrow steps he opened the manhole. The next instant he was helping the princess into the dark passage which he dared not light yet. The flashlight which he also carried for this very emergency, however, enabled all to see their way quite well. But their good fortune was not to continue indefinitely. Hardly had the princess and her father stepped into the _Sphere_ when there came a sound of excited pursuit on the other side of the garden wall which divided the princess’ section from theirs, and the garden gate burst open!