is a shadowy suspicion in my mind that the assassin is interested in the Tolford estate, if you must know, but I may be entirely mistaken. Still, we must remember that on the occasion when the Tolford papers were in the office over night, there was an attempt at robbery. This may be a coincidence, but it is worth looking into."

"I should say so," cried Fremont, with enthusiasm. "I should say it was worth looking into. Now I begin to see what you mean by coming this way, and why you dodged about on the route down. You think the lost mine man is watching us."

"I don't think anything about it," said Nestor. "I never imagine issues, and I never form theories. One thing I know, and that is that we shall find friends over in Mexico. You may even come upon some of the Black Bears there."

"I hope so," was the cheerful reply.

"In which case," continued Nestor, "you might take the suggested ride down the Rio Grande."

"Not with the mountains in sight, and a lost mine to find," exclaimed Fremont.

"And a brutal assassin to bring to punishment," added Nestor.

"And the third motive for visiting Mexico to develop," smiled Fremont. "I wish I knew about that third motive. I understand the first two—one you told me and one I guessed."

"You shall know the other in time," said Nestor. "Just at present, however, the secret is not mine. Important issues are at stake, and I must keep my lips shut, even when talking with you, concerning our mission."

"All right," said Fremont. "Don't worry about me. I'll get it out of you in some way. See if I don't."

Shortly after this conversation closed Nestor went out into the city to arrange for the trip to the mountains. As he left the little hotel he imagined that he saw men bearing unmistakable stamp of plain-clothes policemen hanging about, and it also seemed to him that he was followed as he walked down the crowded street toward the river.

It was late when he returned to the room where he had left Fremont. His suspicions had proven to be more than suspicions, for he had indeed been tracked from the hotel, and had been obliged to do a great deal of walking in order to leave his pursuers behind. When he entered the hotel he saw that the plain-clothes men were no longer on duty at the front.

He climbed the stairs to his room and opened the door with a little quiver of the lips, for the place was dark and silent. When he turned on the lights, however, he was easier in his mind, for there was the sleeping figure he had hoped to find.

In a moment, however, his eyes fell upon a heap of clothing lying across a chair near the head of the bed. Those were not the clothes Fremont had worn. These were soiled and torn. Whose were they, then, and how was it that they were there?

He shook the sleeper lightly and a dust-marked face was lifted from the sheltering bed-clothes. But the face was not that of Fremont, but of Jimmie McGraw. Nestor started back in wonder. How had the boy come there, and where was Fremont? Had he been taken by the police? Was he already on his way back to the tombs? Then Jimmie sprang out of bed with a grin on his face.