“Bless my fountain pen!” exclaimed Mr. Damon, as he caught sight of Tom and Ned in the flickering light of the smudge fire between the two canvas shelters.  “We were just wondering what had become of you.”

“We were chasing shadows!” laughed Tom.  “At least Ned was.  But you look cozy enough in there.”

It did, indeed, look cheerful in contrast to the damp and dark jungle all about.  Professor Bumper, being an experienced traveler, knew how to provide for such comforts as were possible.  Folding cots had been opened for himself, Mr. Damon and the guide to sleep on, others, similar, being set up in the tent where Tom and Ned were to sleep.  In the middle of the tent the professor had made a table of his own and Mr. Damon’s suit cases, and on this placed a small dry battery electric light.  He was making some notes, doubtless for a future book.  Jacinto was going about the camp, seeing that the Indians were at their duties, though most of them had gone directly to sleep after supper.

“Better get inside and under the nets,” advised Professor Bumper to Tom and Ned.  “The mosquitoes here are the worst I ever saw.”

“We’re beginning to believe that,” returned Ned, who was unusually quiet.  “Come on, Tom.  I can’t stand it any longer.  I’m itching in a dozen places now from their bites.”

As Tom and Ned had no wish for a light, which would be sure to attract insects, they entered their tent in the dark, and were soon stretched out in comparative comfort.  Tom was just on the edge of a deep sleep when he heard Ned murmur: 

“I can’t understand it!”

“What’s that?” asked the young inventor.

“I say I can’t understand it.”

“Understand what?”

“That shadow.  It was real and yet——­”

“Oh, go to sleep!” advised Tom, and, turning over, he was soon breathing heavily and regularly, indicating that he, at least, had taken his own advice.

Ned, too, finally succumbed to the overpowering weariness of the first day of travel, and he, too, slept, though it was an uneasy slumber, disturbed by a feeling as though some one were holding a heavy black quilt over his head, preventing him from breathing.

The feeling, sensation or dream—­whatever it was—­perhaps a nightmare—­became at last so real to Ned that he struggled himself into wakefulness.  With an effort he sat up, uttering an inarticulate cry.  To his surprise he was answered.  Some one asked: 

“What is the matter?”

“Who—­who are you?” asked Ned quickly, trying to peer through the darkness.

“This is Jacinto—­your guide,” was the soft answer.  “I was walking about camp and, hearing you murmuring, I came to your tent.  Is anything wrong?”

For a moment Ned did not answer.  He listened and could tell by the continued heavy and regular breathing of his chum that Tom was still asleep.

“Are you in our tent?” asked Ned, at length: