"No," I admitted, "that's a page of underground history that I haven't read--and I must confess that I don't know Stewart, either." "Probably not," said the former Secret Service man. "He wasn't connected with any of the branches of the government that get into print very often. As a matter of fact, the very existence of the organization to which he belonged isn't given any too much publicity. Everyone knows of the Secret Service and the men who make the investigations for the Department of Justice and the Post-office Department--but the Department of State, for obvious reasons, conducts its inquiries in a rather more diplomatic manner. Its agents have to pose as commercial investigators, or something else equally as prosaic. Their salaries are, as a general thing, paid out of the President's private allowance or out of the fund given to the department 'for use as it may see fit.' Less than half a dozen people know the actual status of the organization or the names of its members at any one time, and its exploits are recorded only in the archives of the State Department." "But who," I persisted, as Quinn stopped, "was Jack Stewart and what was the nature of the affair upon which he stumbled in Mexico City?" * * * * * Stewart [replied Quinn] was just a quiet, ordinary sort of chap, the kind that you'd expect to find behind a desk in the State Department, sorting out consular reports and handling routine stuff. Nothing exceptional about him at all--which was probably one reason for his being selected for work as a secret agent of the Department. It doesn't do, you know, to pick men who are conspicuous, either in their dress or manner. Too easy to spot and remember them. The chap who's swallowed up in the crowd is the one who can get by with a whole lot of quiet work without being suspected. When they sent Jack down to Mexico they didn't have the slightest idea he'd uncover anything as big as he did. The country south of the Rio Grande, if you recall, had been none too quiet for some time prior to 1914. Taft had had his troubles with it ever since the end of the Diaz regime, and when Wilson came in the "Mexican question" was a legacy that caused the men in the State Department to spend a good many sleepless nights. All sorts of rumors, most of them wild and bloody, floated up through official and unofficial channels. The one fact that seemed to be certain was that Mexico was none too friendly to the United States, and that some other nation was behind this feeling, keeping it constantly stirred up and overlooking no opportunity to add fuel to the flame. Three or four other members of the State Department's secret organization had been wandering around picking up leads for some months past and, upon the return of one of these to Washington, Stewart was sent to replace him.