have heard about my arrest, and they have arranged for our release—secretly of course. This guard is affiliated with the Nihilist group that got on the trail of my brother. He bribed the other guard to let him take his place for to-night, and now"
"Yes! What is it?" cried Tom.
"He's going to open the cell doors and let us out!"
"But how can we get past the other guards, upstairs?" asked Ned.
"We're not going that way," explained Mr. Petrofsky. "There is a secret exit from this corridor, through a tunnel that connects with a large salt mine. Once we are in there we can make our out. We'll soon be free."
"Ask him if he's heard anything of my airship?" asked Tom. Mr. Petrofsky put the question rapidly in Russian and then translated the answer.
"It's in the same place."
"Hurray!" cried Tom.
Working rapidly, the Nihilist guard soon had the cell doors open, for he had the keys, and our friends stepped out into the corridor.
"This way," called Ivan Petrofsky, as he followed their liberator, who spoke in whispers. "He says he will lead us to the salt mine, tell us
