Conniston and Kent, riding swiftly, side by side, overtook the wagons conveying the three hundred men to the Valley, and, passing them, arrived at Brayley's camp before the men there had quit work for the day. Brayley was more than half expecting them, as Kent had telephoned to the office from Bolton to learn where Conniston was and had told Tommy Garton of his errand.

"An' now," proclaimed Brayley, with deep satisfaction, "we'll have the big ditch clean through Valley City an' the cross-ditches growin' real fast before a week's up."

"I've told the drivers to stop when they get here, Brayley. Some of the men have blankets with them. We can rush more from Mr. Crawford's store in Crawfordsville. We can make out as to food. Have you figured out what more horses, what further tools you'll need? That's good. Send a man to the Half Moon right now with word to Rawhide Jones to rush us the horses. Put your new men to work in the morning if you have to make them dig ditch with shovels. Also send a hundred of them into Valley City as soon as it's daylight to begin the cross-ditches. Let Ben go with them. He can get his instructions there from me or from Tommy Garton. How is everything going?"

Brayley reported that the work was running smoothly, that his foremen were as good men as he ever wanted to see, that he had no fault to find anywhere.

"An' this ol' ditch is sure growin', Con," he finished, with a sudden gleam of pride.

Conniston did not wait for the arrival of the wagons to ride on into Valley City. Kent he left behind him at the camp.

"I've a tremendous curiosity to see how you do this sort of thing," Kent confided to him, as he handed Conniston the message he wished sent from Valley City to Clayton & Paxton, of Denver. "I think that if Mr. Brayley has no objections and can spare me a blanket and some bread and coffee I'll roost here and watch the ditch grow in the morning."

Tommy Garton was still perched upon his high stool when Conniston came to the office.

"Just through, though," he said, as he climbed down and with the aid of his crutches piloted his new legs toward the door, grasping Conniston's hand warmly. "Good news, eh, Greek?"

"The best, Tommy. If we don't put this thing across now we ought to be kicked from one end of the desert to the other. By the way, I had a visit from Swinnerton this afternoon."

He told of what had passed, and ended, thoughtfully:

"What do you suppose was his object, Tommy? Just wanted to get a peek at what we have done?"

Garton laughed softly.

"You poor old innocent. Don't you know what the little man was after? Didn't he make it plain that he wanted you to double cross the old man? Didn't he make it plain that he was in a position to make it worth your while? If our scheme fails, don't you see that you can go to Swinnerton and demand and get a good job working for his scheme? He has bought many a man, Greek. It is his theory that he can buy any man he wants to buy."

"And I let him get away without slapping his little red face," muttered Conniston, disgustedly.

He left Garton a few minutes later, promising to return and spend the night with him, to talk at length with him in the morning, and went down the street to the Crawford cottage. He knew that since Argyl's father had left for Denver Mrs. Ridley, the wife of the proprietor of the lunch-stand, had been staying with her. It was Mrs. Ridley who answered his knock.

"Miss Argyl ain't come back yet, Mr. Conniston," she told him. "She went out this mornin' an' ain't showed up since. I reckon, though, she'll be back real soon now. It's after supper-time already."

"Do you know where she went?"

"No, sir. She didn't say. Won't you come in an' wait for her?"

"No," he answered, after a moment. "I'd better not. If Miss Crawford has been all day in the saddle she will be tired. I'll drop in in the morning."

"Maybe that would be better," Mrs. Ridley nodded at him. "We're up early—breakfast at five. You might run in an' eat with us?"

Conniston promised to do so, and returned to the office, more than a little disappointed at not having seen Argyl, wondering whither her long ride could have taken her. Until late that night he and Garton talked, planned, and prepared for the work of to-morrow. It was barely five the next morning when he again knocked at the cottage door. Again Mrs. Ridley answered his knock.

"Am I too early?" Conniston smiled at her. "I noticed your smoke going. Is Miss Crawford up yet?"

"Miss Crawford—" He saw that she hesitated, saw a nervous uneasiness in her manner as she plucked with quick fingers at the hem of her apron. "She ain't come in yet!"

"What!" cried Conniston, sharply. "What do you mean? Where is she?"

"I—I don't know, sir. She ain't come back yet."

"You mean that Miss Crawford left yesterday morning and that she has not returned since that time? That she has been gone twenty-four hours—all night?"

"Yes, sir." The old woman was eying him with eyes into which a positive fear was creeping, her lips trembling as she spoke. "You don't think anything has happened—"

"I don't know!" he cried, sternly. "Why didn't you let me know last night?"

"I didn't know what to do." The tears had actually sprung into her eyes. "I thought she must be all right. I thought mebbe she'd gone to Crawfordsville or to the Half Moon."

Conniston left her abruptly and hastened to the office.

"Tommy," he called, from the doorway, "do you know where Miss Crawford is? Where she went yesterday?"

"No. Why?" Garton, sensing from the other's tones that something was wrong, swept up his crutches and hurried forward.

"She left yesterday morning," Conniston told him, as he went to the desk and picked up the telephone. "She hasn't come back yet. Mrs. Ridley doesn't know anything about her." And to the operator:

"Give me the Crawford house. Quick, please! Yes, in Crawfordsville."

Upon the face of each man there were lines of uneasiness. Garton propped himself up against the desk and lighted a cigarette, his eyes never leaving Conniston's face.

"Can't you get anybody?" he asked, after a moment.

"No. What's that, Central? They don't answer? Then get me the bunk-house at the Half Moon. Yes, please! I'm in a hurry."

It was Lonesome Pete who answered.

"No, Con," he answered. "Miss Argyl ain't here. Anything the matter?"

Conniston clicked up the receiver and swung upon Garton.

"It is just possible," he said, slowly, "that she is in Crawfordsville, after all. May have left the house already. I can call up the store as soon as it opens up and ask if she has been there."

Billy Jordan had entered at the last words.

"Who are you talking about?" he asked, quickly. "Not Miss Crawford?"

"Yes." Conniston whirled upon him abruptly. "Do you know where she went yesterday?"

"No, I don't know where she went. But as I was coming to the office I met her, just getting on her horse in front of her house, and she gave me a message for you."

"Well, what was it?"

"'If you see Mr. Conniston,' she said, 'tell him that I have gone to investigate the value of the Secret.' I don't know what she meant—"

"She said that!" cried Conniston, his face going white.

"But she's all right," Billy Jordan hastened to add. "She's back now."

"You saw her?"

"No." He shook his head. "But I saw the horse she was riding. Just noticed him tied to the back fence as I came in."

Again Conniston hurried to the cottage. Mrs. Ridley was upon the porch.

"Miss Crawford is back?" he called to her from the street.

She shook her head.

"Not yet. Ain't you—"

He did not wait to listen. Running now, he came to the little back yard, and to a tall bay horse, saddled and bridled, standing quietly at the fence. At first glance he thought, as Billy Jordan had thought, that the animal was tied there. And then he saw that the bridle-reins were upon the ground, that they had been trampled upon and broken, that the two stirrups were hanging upside down in the stirrup leathers as stirrups are likely to do when a saddled horse has been running riderless.

She had been to investigate the Secret! She had been gone all day, all night! And now her horse had come home without her! He dared not try to think what had happened to her; he knew that she must have dismounted while at the spring to examine the ground; he knew that there were sections of the desert alive with rattlesnakes.

The Great Work which had walked and slept with him for weeks, which had never in a single waking hour been absent from his thoughts, was forgotten as though it had never been. The Great Work was suddenly a trifle, a nothing. It did not matter; nothing in the wide world but one thing mattered. Failure of the Great Work was nothing if only a slender, gray-eyed, frank-souled girl were safe. Success, unless she were there to look into his eyes and see that he had done well, was nothing.

Unheeding Mrs. Ridley's shrill cries, he swung about and ran back to the office.

"Tommy," he cried, hoarsely, "her horse is back—without her! She rode away into the desert yesterday morning. She is out there yet. Billy, my horse is in the shed. Don't stop to saddle, but ride like the very devil out to Brayley's camp. Tell him what has happened. Tell him to rush fifty men on horseback to me. Tell him to see that each man takes two canteens full of water. And, for Heaven's sake, Billy, hurry!"