telegram, there had been a letter for him—a letter from his friend, Jack Baxter, to whom he had written of his coming. Jack had left the city on business, it appeared, but he urged Orme to make free of his North Side apartment. So Orme left the Annex and went to the rather too gorgeous, but very luxurious Père Marquette, where he found that the staff had been instructed to keep a close eye on his comfort. All this had happened but three short hours ago.

After getting back to the apartment, Orme’s first thought was to telephone to Bessie Wallingham. He decided, however, to wait till after dinner. He did not like to appear too eager. So he went down to the public dining-room and ate what was placed before him, and returned to his apartment just at dusk.

In a few moments he got Bessie Wallingham on the wire.

“Why, Robert Orme!” she exclaimed. “Wherever did you come from?”

“The usual place. Are you and Tom at home this evening?”

“I’m so sorry. We’re going out with some new friends. Wish I knew them well enough to ask you along. Can you have some golf with us at Arradale to-morrow afternoon?”

“Delighted! Say, Bessie, do you know a girl who runs a black touring-car?”

“What?”

“Do you know a tall, dark girl who has a black touring-car?”

“I know lots of tall, dark girls, and several of them have black touring-cars. Why?”

“Who are they?”

There was a pause and a little chuckle; then: “Now, Bob, that won’t do. You must tell me all about it to-morrow. Call for us in time to catch the one-four.”

That was all that Orme could get out of her and after a little banter and a brief exchange of greetings with Tom, who was called to the telephone by his wife, the wire was permitted to rest.

Orme pushed a chair to the window of the sitting-room and smoked lazily, looking out over the beautiful expanse of Lake Michigan, which reflected from its glassy surface the wonderful opalescence of early evening. He seemed to have set forth on a new and adventurous road. How strangely the girl of the car had come into his life!

Then he thought of the five-dollar bill, with the curious inscription. He took it from his pocket-book and examined it by the fading light. The words ran the full length of the face. Orme noticed that the writing had a foreign look. There were flourishes which seemed distinctly un-American.

He turned the bill over. Apparently there was no writing on the back, but as he looked more closely he saw a dark blur in the upper left-hand corner. Even in the dusk he could make out that this was not a spot of dirt; the edges were defined too distinctly for a smudge; and it was not black enough for an ink-blot.

Moving to the center-table, he switched on the electric lamp, and looked at the blur again. It stood out plainly now, a series of letters and numbers:

The first thought that came to Orme was that this could be no hoax. A joker would have made the curious cryptogram more conspicuous. But what did it mean? Was it a secret formula? Did it give the location of a buried treasure? And why in the name of common sense had it been written on a five-dollar bill?

More likely, Orme reasoned, it concealed information for or about some person—“S. R. Evans,” probably. And who was this S. R. Evans?

The better to study the mystery, Orme copied the inscription on a sheet of note-paper, which he found in the table drawer. From the first he decided that there was no cipher. The letters undoubtedly were abbreviations. “Evans” must be, as he had already determined, a man’s name. “Chi” might be, probably was, “Chicago.” “100 N. 210 E.” looked like “100 (feet? paces?) north, 210 (feet? paces?) east.”

The “A.” and the “T.” bothered him. “A.” might be the place to which “S. R. Evans” was directed, or at which he was to be found—a place sufficiently indicated by the letter. Now as to the “T.”—was it “treasure”? Or was it “time”? Or “true”? Orme had no way of telling. It might even be the initial of the person who had penned the instructions.

Without knowing where “A.” was, Orme could make nothing of the cryptogram. For that matter, he realized that unless the secret were criminal it was not his affair. But he knew that legitimate business information is seldom transmitted by such mysterious means.

Again and again he went over the abbreviations, but the more closely he studied them, the more baffling he found them. The real meaning appeared to hinge on the “A.” and the “T.” Eventually he was driven to the conclusion that those two letters could not be understood by anyone who was not already partly in the secret, if secret it was. It occurred to him to have the city directory sent up to him. He might then find the address of “S. R. Evans,” if that person happened to be a Chicagoan. But it was quite likely that the “Chi.” might mean something other than that “Evans” lived in Chicago. Perhaps, in the morning he would satisfy his curiosity about “S. R. Evans,” but for the present he lacked the inclination to press the matter that far.

In the midst of his puzzling, the telephone-bell rang. He crossed the room and put the receiver to his ear. “Yes?” he questioned.

The clerk’s voice answered. “Senhor Poritol to see Mr. Orme.”

“Who?”

“S-e-n-h-o-r—P-o-r-i-t-o-l,” spelled the clerk.

“I don’t know him,” said Orme. “There must be some mistake. Are you sure that he asked for me?”

There was a pause. Orme heard a few scattered words which indicated that the clerk was questioning the stranger. Then came the information: “He says he wishes to see you about a five-dollar bill.”

“Oh!” Orme realized that he had no reason to be surprised. “Well, send him up.”

He hung up the receiver and, returning to the table, put the marked bill back into his pocket-book and slipped into a drawer the paper on which he had copied the inscription.

When Orme answered the knock at the door a singular young man stood at the threshold. He was short, wiry, and very dark. His nose was long and complacently tilted at the end. His eyes were small and very black. His mouth was a wide, uncertain slit. In his hand he carried a light cane and a silk hat of the flat-brimmed French type. And he wore a gray sack suit, pressed and creased with painful exactness.

“Come in, Senhor Poritol,” said Orme, motioning toward a chair.

The little man entered, with short, rapid steps. He drew from his pocket a clean pocket-handkerchief, which he unfolded and spread out on the surface of the table. Upon the handkerchief he carefully placed his hat and then, after an ineffectual effort to make it stand against the table edge, laid his cane on the floor.

Not until all this ceremony had been completed did he appear to notice Orme. But now he turned, widening his face into a smile and extending his hand, which Orme took rather dubiously—it was supple and moist.

“Oh, this is Mr. Orme, is it not?”

“Yes,” said Orme, freeing himself from the unpleasant handshake.

“Mr. Robert Orme?”

“Yes, that is my name. What can I do for you?”

For a moment Senhor Poritol appeared to hover like a