With a suddenness that was startling, he found himself in total
darkness. The candle had burned out, but he had his finger on the
screw. He pressed it with all his force.

There was a rumbling sound in the darkness, a movement as if some heavy
body had slid out of the way, and Mark felt a breath of air on his
cheeks. Then he saw a dim light.

"Oh, I'm out! I'm out!" he cried joyously, breathing a prayer of
thankfulness at his deliverance. "I'm free! I pushed on the right
spring, and the panel slid back!"

He fairly leaped forward. The morning light was streaming in through
the broken windows. He saw himself in the old hall of the mansion, at
the head of the stairs, in a sort of anteroom, the mantle of which
apartment had swung aside to give him egress from the secret chamber
through a hole in the wall. He was free!

"But am I in time?" he cried. "It is morning--and about ten o'clock, I
should judge. I've been working to get free all night. Will I be in
time?"

He gave one last look behind at his prison and sprang down the rickety
stairs. He had but one thought--to reach home in time to unmask the
villain who was impersonating him--to be in time to make the journey to
the moon.

"But it's several miles, and I can't walk very fast," murmured Mark.
"I'm too stiff and weak. How can I do it?"