THE three caught sight of the helicopter in the same instant. The strange machine was rushing through the air like a colossal eagle. Professor Morgan had seen the group while some distance away and headed for it, sailing at a height of less than two hundred feet and rapidly descending. Instead of approaching in a direct line, he made a sweeping circle and came down in the ordinary way by volplaning instead of making use of his uplifter.  
While these manœuvres were going on Dick Hamilton stepped across to his brother and reached out his hand.
 
“Let me have the rifle, Harv; it looks as if we’re going to have lively times.”
 
“Gee!” gasped the terrified Bunk; “yo’ ain’t gwine to shoot him!”
 
“That depends; if you try any tantrums I may have to plug you first. Understand, Bunk, that you are to stand back and not open your mouth or do a thing till I give you permission.”
 
“Yas, sir.”
 
Harvey would have made protest, for he was filled with shuddering dread, but he realized that for the present he stood in the same situation as Bunk. The big brother had stepped to the front and taken charge of affairs. Moreover, he never forgot the truth that in dealing with an insane person you must first impress him with the fact that you do not hold him in the slightest fear. While as a rule it is not wise to dispute or argue or try to turn him aside from his purpose by force, occasions may arise like the present when no other course is possible.
 
Professor Morgan must have read the meaning of the sight that brought him to the spot. He recognized Harvey before he stepped out of his machine and his rage flamed up against him. Ignoring the other two, he strode toward the young aviator with clenched fists and with murder in his blazing eyes. In a thunderous bass he demanded:
 
“What business have you here? I’ll teach you—”
 
He had said this much and his long legs were still in motion, when Dick leaped between them and holding his rifle at his hip with muzzle leveled at the infuriated man, he commanded:
 
“Stop! if you touch him I’ll let daylight through you!”
 
The Professor halted and turned upon the other, his frame trembling with surcharged fury.
 
“I’ll kill you!”
 
It is impossible to picture the frightful scene at this moment. Bunk Johnson was silent and awed. Harvey was a little to one side and in front of him, while in the other direction stood Dick, one foot advanced as if ready to bound forward, his right hand inclosing the lock of his gun, so that the forefinger could be seen crooked around the trigger. The weapon was so pointed that only a slight pressure was needed to send a bullet through the long gaunt body hardly a dozen feet away.
 
“All right,” calmly replied Dick; “you can begin as soon as you please, my distinguished friend, but before you reach me you will have to stop ten spheres of lead and by that time I calculate I shall be able to handle you without the need of my Winchester.”
 
Professor Morgan may have been “off his base,” but he could not fail to read the meaning of those words, backed up by the pose of him who uttered them. He stopped like a tiger baffled of his prey.
 
“Why don’t you shoot?” he hissed.
 
“You haven’t given me the excuse I’m waiting for; in the case of every one of the seven men I have shot my explanation secured my acquittal[261] in the courts. I’m taking the same course with you.”
 
The sight of Harvey seemed to concentrate once more the lunatic’s resentment against him. But for the presence of that Winchester and the man behind the gun, he would have rended the youth, provided the latter did not stand him off with his Colt.
 
“What business, I demand, have you to come here?”
 
“Please address your remarks to me,” said Dick; “I’m boss of this job and that brother of mine over there hasn’t a word to say. He came up here, I may tell you, to take Bohunkus Johnson home with him, and he’s going to do it as sure as two and two make four. If you have any views to express on the situation do so now or forever after hold your peace.”
 
Checked thus the Professor turned toward the paralyzed Bunk.
 
“Do you wish to go with me to Africa?”
 
“Yas, sir.”............