"In there?" cried Tom.
"In there," answered Mr. Petrofsky. He and the guard murmured their good-byes, and then, with a lighted candle the faithful Nihilist had provided, and with several others in reserve, our friends stepped into the blackness. They could hear the board being pulled back into place behind them.
"Forward!" cried the exile, and forward they went.
It was not a pleasant journey, being through an uneven tunnel in the darkness. Half a mile later they emerged into a large salt mine, that seemed to be directly beneath the town. Work in this part had been abandoned long ago, all the salt there was left being in the shape of large pillars, that supported the roof. It sparkled dully in the candle light.
"Now let me see if I remember the turnings," murmured Mr. Petrofsky. "He said to keep on for half an hour, and we would come out in a little woods not far from where our airship was anchored."
Twisting and turning, here and there in the semi-darkness, stumbling, and sometimes falling over the uneven floor, the little party went on.
"Did you say half an hour?" asked Tom, after a while.
"Yes," replied the Russian.
"We've been longer than that," announced the young inventor, after a look at his watch. "It's over an hour."
"Bless my timetable!" cried Mr. Damon.