“Where are you, Frank?” called Andy.

“Right here. Give me your hand. It won’t do to get lost in this darkness. Where are you?”

The two brothers groped about in the darkness until they had found each other.

“Listen,” whispered the older one. “Do you hear him?”

In the silence and blackness there came to them the sound of retreating footsteps, and of small stones and particles of earth falling.

“He must be climbing up,” said Andy. “This cave is bigger than we thought, and he must know the place, even in the dark.

“It is as dark as a pocket,” complained Frank. “I can’t see anything.”

“Wait!” suddenly exclaimed Andy. “Why didn’t we think of them before? Our pocket electrics. They’ll do the trick!”

“Sure enough.”

An instant later two small but powerful gleams of light cut the blackness of the cavern, and the boys were enabled to see so they could hurry ahead. They could still hear the man retreating before them.

“We’re coming!” cried Andy in reckless bravado.

“Hush! He’ll hear you,” cautioned his brother.

“What of it? I want him to. He’ll see our lights anyhow. But I think we have him trapped.”

“If there isn’t another outlet to the cave. But come on.”

Forward they pressed. They could still hear the noise made by the man, and once they were startled by his mocking laugh. So close was it that they knew he must have doubled on his tracks and returned toward them.

“There are several passages in this cave, I’m sure of it,” declared Frank. “We’ll have to be careful not to get lost.”

“That’s right. This fellow must be at home here. But the floor is beginning to slope upward. Say, it’s damp in here, all right,” Andy added, as he stepped into a little puddle of water.

“From the rain, I guess,” replied Frank.

“Hu! How could rain get in here?”

“It must have soaked in through the roof. But we can’t talk and listen for that man. Let’s hurry on.”

Once more they advanced, but they became confused by many windings and turnings of the dark passages, until Frank called a halt.

“Let’s consider a bit,” he said to his brother. “We can’t go on this way. We’ve got to mark some of these passages so we’ll know them again if we come by. Otherwise we’ll get all confused.”

“Good idea. Make some scratches on them with your knife. That will do.”

Frank quickly did this and they pressed on. Occasionally they called to the man, but he did not answer them now—not even by his mocking laugh. They, however, could still hear him.

“He’s leading us on a wild goose chase!” declared Frank at length. “The first thing we know he’ll get back to the entrance and escape.”

“Then one of us had better go to the mouth of the cave and either stop him, or else be there to give the alarm when he tries to get out,” proposed Andy. “I’ll go.”

“No, I think we’d better stick together,” suggested his brother. “That man is too dangerous for one of us to tackle alone. We may catch up to him any moment now, and I hope he’ll give in, and tell us what we want to know.”

Without the portable electric lights which they each carried it would have been impossible for the Racer boys to have found their way about the cave. They marveled how it was that the mysterious man could follow the windings and turnings in the dark, but, as they learned afterward, he had been in the cave before.

Back and forth, up and down, here and there, like following some will-o’-the-wisp went the boys. At times they thought they had lost the object of their pursuit, but again they would hear him hurrying on ahead of them.

“Hold on a minute!” suddenly exclaimed Frank, when he had led the way down a steep descent. “I don’t like this.”

“Like what?” asked Andy, in some alarm.

“This chase. That man knows what he’s doing and we don’t. If he wanted to he could have been out of this cave a dozen times or more, yet he’s staying in and leading us on. He has some............