"I'm sorry, sir," urged Neville, "we can't go into that now. Do what you want to with me afterwards, but I assure you this is urgent. I am on the trail of a higher-up in the Callisto-Trojan extortion racket. Do I get the information I am after, or do I turn in my agent badge?" "Huh?" said the old general, sitting up and looking him straight in the face. "What's that?" "I mean it, sir. I have trailed one of the higher-up stooges to Earth and set shadows on him. I _think_ I have seen the king-pin of the mob, and I want to know who he is," Neville went on to describe the presentation of the showboat entertainment, with special emphasis on his hunches and suspicions. To the civilian mind, the things he told might seem silly, but to a policeman they were fraught with meaning. His description of the suspect was not one of appearance; it was a psychological description--a description based wholly on intuition and not at all on tangibles. He had not proceeded far before the wrinkled old man thumped the desk with a gnarled fist. "Hold it," he said, "I think I know the man you mean. But give me time--my memory is not what it used to be." Neville waited patiently at the rigid attitude of attention while the shriveled old veteran before him rocked back and forth in his chair with the lids closed over his bulging eyes, cracking his bony knuckles like castanets. O'Hara seemed to have gone into something like a trance. Suddenly, after a quiver of the eyelids, he stared up at Neville. "It all comes back now. You were a member of the class of '14 and I was instructor--a major then. I took all of you to see a certain show on Broadway, as they call it, in order...." "Yes, sir," cried Neville, eagerly, "that was it! You told us the principal character in the play was the most dangerous potential criminal of our generation and that we should mark him well and remember. It was a very hard assignment, for we only saw him from before the foot-lights and he was acting the part of a Viking chieftain and most of his face was covered with false white whiskers." Old O'Hara smiled. "You seem to have been an apt pupil. At any rate, that man was Milo Lunko, a thoroughly unprincipled and remarkably clever blackmailer. He was so clever, in fact, that we were never able to make an arrest stick, let alone bring him to trial. That accounts for the absence of his picture from the gallery. He was also clever enough to fake his own death. The evidence we have as to that was so convincing we closed the file on him." "It's open again," said Neville grimly. "How did he work?" * * * * *