Bad Pete took a step forward, dropping his right hand, as though unconsciously, to the butt of the revolver in the holster. He fixed his burning gaze savagely on the boy’s face as he muttered, in a low, ugly voice: “Tenderfoot, when I’m around after this you shut your mouth and keep it shut! You needn’t take the trouble to call me Peter again, either. My name is Bad Pete, and I am bad. I’m poison! Understand? Poison!” “Poison?” repeated Tom dryly, coolly. “No; I don’t believe I’d call you that. I think I’d call you a bluff---and let it go at that.” Bad Pete scowled angrily. Again his hand slid to the butt of his revolver, then with a muttered imprecation he turned and stalked away, calling back threateningly over his shoulder: “Remember, tenderfoot. Keep out of my way.” Behind the boys, halted a man who had just stepped into the camp over the natural stone wall. This man was a sun-browned, smooth-faced, pleasant-featured man of perhaps thirty-two or thirty-three years. Dressed in khaki trousers, with blue flannel shirt, sombrero and well-worn puttee leggings, he might have been mistaken for a soldier. Though his eyes were pleasant to look at, there was an expression of great shrewdness in them. The lines around his mouth bespoke the man’s firmness. He was about five-feet-eight in height, slim and had the general bearing of a strong man accustomed to hard work. “Boys,” he began in a low voice, whereat both Tom and Harry faced swiftly about, “you shouldn’t rile Bad Pete that way. He’s an ugly character, who carries all he knows of law in his holsters, and we’re a long way from the sheriff’s officers.” “Is he really bad?” asked Tom innocently. “Really bad?” laughed the man in khaki. “You’ll find out if you try to cross him. Are you visiting the camp?” “Reade! Hazelton!” called a voice brusquely from the big tent. “That’s Mr. Thurston calling us, I guess,” said Tom quickly. “We’ll have to excuse ourselves and go and report to him.” “Yes, that was Thurston,” nodded the slim man. “And I’m Blaisdell, the assistant engineer. I’ll go along with you.” Throwing aside the canvas flap, Mr. Blaisdell led the boys inside the big tent. At one end a portion of the tent was curtained off, and this was presumably the chief engineer’s bedroom. Near the centre of the tent was a flat table about six by ten feet. Just at present it held many drawings, all arranged in orderly piles. Not far from the big table was a smaller one on which a typewriting machine rested. The man who sat at the large table, and who wheeled about in a revolving chair as Tom and Harry entered, was perhaps forty-five years of age. His head was covered with a mass of bushy black hair. His face was as swarthy, in its clean-shaven condition, as though the owner had spent all of his life under a hot sun. His clothing like that of all the rest of the engineers in camp was of khaki, his shirt of blue flannel, with a long, flowing black tie.