Once more there sounded an unmistakable groan. It came from the ground floor, and was so loud, penetrating and, in spite of the would-be bravery of the boys, so awful coming out of the darkness, that they shuddered.
“What’s that?” asked the professor, who also, this time, was roused from his slumbers.
Before either of the boys could answer the groan was repeated and this time it was followed by the unmistakable clanking of chains.
“The colored man’s ghost!” whispered Bob.
“Nonsense!” exclaimed the professor, but, no sooner had he spoken than there came another weird noise, and the chains rattled louder than ever.
“Light the lantern,” whispered Jerry. “We must see what it is. Perhaps it’s only some one playing a joke.”
“Let me take a look before you make a light,” suggested the professor. “I can look down the ladder hole.”
Softly he crawled over to the opening and peered down. As he did so the noises were repeated. The professor uttered an exclamation.
“It bears the other descriptive marks of the creature the negro told about,” he said, crawling back to where the boys were huddled together. “It is big and white and it seems to be trying to climb up the ladder.”