"How did that beast get up here?" demanded Mr. Sparling.

"Who, Cummings?" asked Teddy innocently.

"No, no! The donkey."

"Oh! Maybe he came up through the smoke stack. If you will look at it you may find donkey tracks on the inside of the stack."

"That will do, that will do, young man."

It was found upon investigation that January had gnawed his halter until only a thin strand held it together, which was easy for the donkey to break. Then he began an investigation of the boat, ending by his climbing the broad staircase and frightening the pilot.

Next morning the pilot house looked as though it had been through a shipwreck. The whole craft, in fact the entire fleet, was laughing at the expense of Cummings, who now kept to himself, studiously avoiding the other people. January was tied up with a dog chain after that, and was not heard from again during any trip of that season; that is, beyond his regular acts in the sawdust arena.

The next day Phil Forrest began his investigation in earnest. He knew that Mr. Sparling looked to him to discover who had caused so much trouble in the show, besides which, Phil took a personal interest because of the attempt that had been made on the lives of Little Dimples and himself.

Teddy suggested that he go through the pilot's belongings, expressing the firm belief that they would find the ostrich egg were they to do so.

Phil consulted Little Dimples, that afternoon, as to her opinion of the occurrences of the past week, but the star bareback rider could shed no light on them, beyond the fact that certain people with whom Phil had had difficulties might bear watching.

"That's what I think," answered the Circus Boy. "I do not like to accuse anyone unjustly, but I have these suspicions of the Spanish clown."

"Have you mentioned your suspicion to Mr. Sparling, Phil?"

"No."

"Do you intend to do so?"

"Not unless I find some facts to support my suspicion."

"You will get to the bottom of the mystery, I am sure," smiled the woman.

"I am not so sure. Why do you think so?"

"Because you are one of the cleverest boys I ever knew, that's why. I should hate to have you on my track if I were guilty of any particular crime that you were trying to run down. I should expect to land in jail, and I think I should come straight to you and give myself up," added the woman with a merry laugh.

"I wish I were all that you think I am, Dimples."

"You are. You saved my life again yesterday. I'm going to pay you back, however. Someday, when you fall overboard, Little Dimples is going to jump right in and rescue you--haul you out by the hair of your head--"

"You can't, it is cut too short."

"Then I will pull you out by an ear."

"I shall make it my business to fall in, then, at the first opportunity," laughed Phil. "It would be worthwhile."

Dimples gave him a playful tap.

"You can turn a compliment as well as you can do a turn in the ring, can't you Phil Forrest?"

Despite their narrow escape from serious accident, Phil and Dimples went through their double act in the ring that day and evening with perfect confidence. Previous to going on, Phil had had a ring attendant go over the sawdust circle on his hands and knees, making a careful examination of it, to be sure that the ring had not been tampered with.

From that time on until the act went on, the ring was watched, though Phil did not believe the miscreant would attempt to lay another trap for him so soon. Still, he took nothing for granted.

That night after the performance, the air being warm and balmy, the Circus Boy strolled out on the lot, sitting down on a little knoll to think matters over. There was plenty of time, for the boat would not leave for two or three hours, and Phil wanted to be alone.

Lights were twinkling on the lot like fireflies. There was shouting and singing, but little of this conveyed itself to Phil, for his mind was on other things.

All at once he pricked up his ears. He caught the sound of running footsteps.

"Someone is coming this way," he muttered. "I wonder what that means? Surely none of the circus people would come here. They would go around by the road."

The lad concealed himself behind the knoll, peering over the top of it. He resolved not to show himself until he had discovered the identity of the newcomers.

They proved to be two men who halted a short distance beyond him, and began to converse in guarded tones. It was so dark that Phil could scarcely distinguish their figures and their voices were pitched so low that it was impossible for him to hear what they were saying.

"This looks queer," Phil muttered. "I wish I could hear what they are talking about. Perhaps they are town fellows who have been chased off the lot because they were in the way. At any rate, I'm going to try to find out what they are up to. Hello, they are coming right over here."

Phil crouched down behind the knoll and listened. The men turned slowly and came toward him. All at once one of them stumbled on the very knoll behind which he was secreted.

The man uttered a growl.

"Come, sit down," he said to his companion.

"We better go on," answered the other.

"No hurry. We've got all the time in the world. If we miss the boat we can swim. That was a narrow escape. In a minute more we'd had that wagon fixed so they would never have got off the lot with it."

"Hello," muttered Phil under his breath. "Something surely is going on here. One of the voices I have heard before, and the other I seem to recognize. I believe that first fellow belongs to the show. I am almost sure of it."

"You think the fellow suspects?"

"The tall one does. But he doesn't know whom be suspects."

"We have to take care."

"Yes."

"But we will get both before the end of the season."

"You bet we will. I have a plan that--"

"What is it?"

"It is this."

Phil had buried his head in the grass and compressed his body into the smallest possible space that he might avoid discovery. He could hear the two men breathe, and he reasoned that they might hear him as well.

"You know the big net?"

"You mean the one over which the flying four perform?"

"Yes."

"What about it?"

"It can be fixed."

"How?"

"By weakening some of the strands on each side."

"That is good, but suppose someone noticed."

"Not if it is done right. I don't mean to do it all at once. I'll doctor one or two strands every day until the net is so weakened that it won't hold."

"Yes, but how will you do this so no one will see?"

"I'll tell you. After the act is over they roll the net up and carry it out. It is dumped just outside the pad room, where it is picked up by one of the property wagons later in the evening. It's in the same place every night."

"I think somebody may see us do it."

"No danger. Keep cool; that's all. We'll get even with those fellows. We have got to before we can carry out the other plans we have talked over. They are too sharp. Sooner or later they will get wise to us, and we've got to get them out of the way before we go any further. The work must be done in a natural sort of way, so that no suspicion is aroused."

"Yes, that's so. But what about the others? You want to hurt them, too?"

"I don't care, so long as we get the right one, how many get their bumps."

"That's right. But only one of them is on trapeze. What you do about other?"

"It is the tall one that I want most. He's got to be put out of the running. It won't kill him, but it will lay him up in a hospital for the rest of the season, and that's enough for us."

"Yes."

"The other one will be taken care of after we get through with the first. The small fellow is sharp, but he can't see beyond his nose. It's easy to fool him."

"The fiends!" muttered Phil. "I believe they are plotting against Teddy and me. I have a good notion to sail into them right here and settle it. I believe I could whip the two of them. I--"

At that instant a blade of grass tickled Phil's nose. He raised his head quickly.

"What's that?" exclaimed one of the plotters.

"I heard nothing."

"You didn't? Well, I did. There's someone around here and close by us."

"Perhaps it was a squirrel in the grass. There is no one here."

The blade of grass had done its work, however. Phil tried hard to control himself, but he knew he was going to sneeze.

All at once the sneeze came, louder than he had ever sneezed before.

The men leaped to their feet in sudden alarm.