"Heaven grant that he may be there!" said the exile in a low voice.
A moment later, the Falcon, meanwhile having been allowed to drift as close as possible to the dimly-seen line of prisoners, Tom set in motion the great motor, the propeller blades heating the air fiercely.
At the sound there was a shout on the ground below, but before the excitement had time to spread, or before any of the guards could form a notion of what was about to take place, Tom had sent his craft to earth on a sharp slant, closer to the line of prisoners than he had dared to hope.
Mr. Petrofsky sprang out on deck, and in a loud voice called in Russian:
"Peter! Peter! If you are there, come here! Come quickly! It is I, your brother Ivan who speaks. I have come to save you—save you in the wonderful airship of Tom Swift! Come quickly and we will take you away! Peter Petrofsky!"
For a moment there was silence, and then the sound of some one running rapidly was borne to the ears of the waiting ones. It was followed, a moment later, by angry shouts from the guards.
"Quick! Quick, Peter!" cried the brother, "over this way!"
For an instant only the exile showed a single electric flash light, that his brother might see in which direction to run. The echo of the approaching footsteps came nearer, the shouts of the guards redoubled, and then came the sound of many men running in pursuit.
"Hurry, Peter, hurry!" cried Mr. Petrofsky, and, as he spoke in Russian the guards, of course, understood.
Suddenly a rifle shot rang out, but the weapon seemed to have been fired in the air. A moment later a dark figure clambered aboard the airship.