"Talk sense!" Sime said contemptously. "If I threw down the service how could you trust me?" "That'd be easy," Balta rejoined. "Once the I. F. P. finds out you joined us you'd have to stick with us to save your skin." He laughed at his prisoners' look of surprise. "Come, come!" he bantered. "You didn't think that I was ignorant of your purpose here? You, Murray; your spying was excellent, I'll admit. You were the first to give away certain plans of ours. Well, well! We don't hold that against you. Wheels within wheels, eh? It would perhaps astonish certain braided gentleman of our high command to learn that I, a mere colonel, control their destinies. As our ancestors would say, it's dog eat dog. "Now, how about it? I can make a place for you in my organization. It seems to run to secret service, oddly enough. You will be rewarded far beyond anything you could expect in your present career of chasing petty crooks from Mercury to Pluto and back again." "Is that all?" Murray asked softly, with a bearded grin. "Oh no. You will turn over to me all the information you can about the I. F. P. helio code. You will name and describe to me each and every plainclothes operative of the service--and you should have an extensive acquaintance." "Before you answer," Murray said quietly at Sime's side, "let me suggest that you consider what's in store for us--or you--if you don't take up this offer." "Why, you--" Sime whirled in astonished fury upon his companion. "Didn't you--" * * * * * But he did not complete his reference to last night's surreptitious conversation. It seemed that he saw the merest ghost of a flicker in Murray's left eye. "--Didn't you say you'd stick no matter what they did?" he finished lamely. Murray hung his head. "I'm getting along," he muttered. "Not as young as I used to be. This life is getting me nowhere. Why be a fool? Come along with me!" "Why, you dirty, double-crossing hound!" Sime's exasperation knew no bounds. For an instant he had believed that Murray was enacting a little side-play in the pursuit of a suddenly conceived plan. But he looked so obviously hangdog--so guiltily defiant.... _Crack!_ Sime's fist struck Murray's solid jaw, scraping the skin off his knuckles, but Murray swayed to the blow, sapping its force, and came in to clinch. They rolled on the floor. Murray twisted Sime's head painfully, bit his ear. But in the next split second he was whispering: "Keep your head, Sime. Can't you see I'm stringing him? Take that!" And he planted a vicious short hook to Sime's midriff. Balta had squalled orders, and now Martian soldiers were bursting the buttons off their uniforms in the scrimmage to separate the battlers. Bruised and battered, they were dragged apart. Murray's one eye was now authentically closed, and rapidly coloring up. Unsteadily he got to his feet. With mock delicacy he threw a kiss to his late antagonist.