When they returned to the veranda Payne sat down on the steps. Jake picked up his chair and looked at him thoughtfully.

“Now,” he said, “I want to know why you have been prowling about the shack at night. You had better begin at the beginning.”

“Very well. I guess you know I was put off this camp soon before you came?”

“I heard something about it,” Jake admitted.

Payne grinned as if he appreciated his tact, and then resumed: “In the settlement where I was raised, the old fellow who kept the store had a cheat-ledger. When somebody traded stale eggs and garden-truck for good groceries, and the storekeeper saw he couldn’t make trouble about it without losing a customer, he said nothing but scored it down against the man. Sometimes he had to wait a long while, but sooner or later he squared the account. Now that’s my plan with Don Ramon Oliva.”

“I see,” said Jake. “What have you against him?”

“To begin with, he got me fired. It was a thing I took my chances of and wouldn’t have blamed him for; but I reckon now your father’s cement wasn’t all he was after. He wanted a pull on me.”

“Why?”

“I haven’t got that quite clear, but I’m an American and could do things he couldn’t, without being suspected.”

“Go on,” said Jake, in a thoughtful tone.

“Well, for a clever man, he made a very poor defense when your partner spotted his game; seemed to say if they reckoned he’d been stealing, he’d let it go at that. Then, when he’d got me and found I wasn’t the man he wanted, he turned me down. Left me to live with breeds and niggers!”

“What do you mean by your not being the man he wanted?”

Payne smiled in a deprecatory way. “I allow that I was willing to make a few dollars on the cement, but working against white men in a dago plot is a different thing.”

“Then there is a plot?”

“Well,” said Payne quietly, “I don’t know much about it, but something’s going on.”

Jake lighted a cigarette while he pondered. He was not surprised that Payne should talk to him with confidential familiarity, because the situation warranted it, and the American workman is not, as a rule, deferential to his employer. The fellow might be mistaken, but he believed that Oliva had schemed to get him into his power and work upon his wish for revenge. Jake could understand Oliva’s error. Payne’s moral code was rudimentary, but he had some racial pride and would not act like a treacherous renegade.

“I begin to see how your account against Oliva stands,” he remarked. “But is that the only entry in your book?”

“I guess not,” Payne replied. “Mr. Brandon’s name is there, but the entry is against myself. It was a straight fight when he had me fired, and he took me back when he found I was down and out.”

Jake nodded. “You have already warned Brandon that he might be in some danger in the town.”

“That’s so. Since then, I reckoned that they were getting after him here, but we were more likely to hold them up if they didn’t know we knew. That’s why I called out to show I thought it was Pepe who was in the shack.”

“Very well,” said Jake. “There’s nothing more to be done in the meantime, but you’d better tell me if you find out anything else.”

Payne went away and when Dick came in Jake took him into his room and indicated the blotter.

“Have you torn off the top sheet in the last few days?”

“I don’t remember doing so, but now I come to look, it has been torn off.”

“What have you been writing lately?”

“Orders for small supplies, specifications of material, and such things.”

“Concrete, in short?” Jake remarked. “Well, it’s not an interesting subject to outsiders and sometimes gets very stale to those who have to handle it. Are you quite sure you haven’t been writing about anything else?”

“I am sure. Why do you ask?”

“Because, as you see, somebody thought it worth while to steal the top sheet of your blotter,” Jake replied. “Now perhaps I’d better tell you something I’ve just learned.”

He related what Payne had told him and concluded: “I’m puzzled about Oliva’s motive. After all, it could hardly be revenge.”

“No,” said Dick, with a thoughtful frown, “I don’t imagine it is.”

“Then what does he expect to gain?”

Dick was silent for a few moments with knitted brows, and then asked: “You have a Monroe Doctrine, haven’t you?”

“We certainly have,” Jake agreed, smiling. “We reaffirmed it not long ago.”

“Roughly speaking, the Doctrine states that no European power can be allowed to set up a naval base or make warlike preparations in any part of America. In fact, you warn all foreigners to keep their hands off?”

“That’s its general purport; but while I support it patriotically, I can’t tell you exactly what it says. Anyhow, I don’t see what this has to do with the matter.”

“Nor do I, but it seems to promise a clue,” Dick answered dryly. He frowned at the blotter and then added: “We’ll leave it at that. I’ve some vague suspicions, but nothing to act upon. If the thing gets any plainer, I’ll let you know.”

“But what about Payne? Is he to hang around here nights with his gun?”

“No,” said Dick, “it isn’t necessary. But there’d be no harm in our taking a few precautions.”

He stretched his arms wearily when Jake left him, for he had had a tiring day and had now been given ground for anxious thought. He had not troubled much about Oliva while he imagined that the fellow was actuated by a personal grudge, but his antagonism began to look more dangerous. Suppose the Adexe coaling station was intended to be something of the nature of a naval base? Munitions and other contraband of war might be quietly sent off with fuel to fighting ships. Richter, the German, had certainly been associated with Kenwardine, who had made an opportunity for telling Jake that they had disagreed. Then suppose the owners of the station had learned that they were being spied upon? Dick admitted that he might not have been as tactful as he thought; and he was employed by an influential American. The Americans might be disposed to insist upon a strict observance of the Monroe Doctrine. Granting all this, if he was to be dealt with, it would be safer to make use of a half-breed who was known to have some ground for hating him.

Dick, however, reflected that he was taking much for granted and his suppositions might well be wrong. It was unwise to attach too much importance to a plausible theory. Then he could not expose Kenwardine without involving Clare, and saw no means of separating them. Besides, Kenwardine’s position was strong. The officials were given to graft, and he had, no doubt, made a skilful use of bribes. Warnings about him would not be listened to, particularly as he was carrying on a thriving business and paying large sums in wages in a country that depended on foreign capital.

Then Dick got up with a frown. His head ached and he was tired after working since sunrise in enervating heat. The puzzle could not be solved now, and he must wait until he found out something more.

For the next two or three evenings he was kept busy at the dam, where work was carried on after dark, and Jake, taking advantage of this, went to Santa Brigida one night when he knew the locomotive would be coming back up the line. Nothing of importance happened at Kenwardine’s, where he did not see Clare, and on his return he took a short cut through a badly-lighted part of the town. There was perhaps some risk in this, but Jake seldom avoided an adventure. Nothing unusual happened as he made his way through the narrow streets, until he reached a corner where a noisy group hung about the end house. As the men did not look sober, he took the other side of the street, where the light of a lamp fell upon him.

His close-fitting white clothes distinguished him from the picturesque untidiness of the rest, and when somebody shouted, “Un Gringo!” one or two moved across as if to stop him. Jake walked on quickly, looking straight in front without seeming to notice the others, in the hope of getting past before they got in his way, but a man dressed like a respectable citizen came round the corner and the peons ran off. Since the appearance of a single stranger did not seem to account for this, Jake wondered what had alarmed them, until he saw a rural guard in white uniform behind the other. When the man came up the rurale stopped and raised his hand as if he meant to salute, but let it fall again, and Jake imagined that the first had given him a warning glance. He knew the thin, dark-faced Spaniard, whom he had met at Kenwardine’s.

The man touched Jake’s shoulder and drew him away, and the lad thought it strange that the rurale went on without asking a question.

“I don’t know that the peons meant to make trouble, but I’m glad you came along, Don Sebastian,” he said.

“It is an honor to have been of some service, but it looks as if you were as rash in other matters as you are at cards,” the Spaniard answered. “These dark calles are unsafe for foreigners.”

“So it seems, but I’m afraid it will be a long time before I’m worth robbing,” Jake replied, and then remembered with embarrassment that the other was one of the party whose winnings he had not yet paid.

Don Sebastian smiled, but said suavely: “For all that, you should not take an unnecessary risk. You have been attacked once already, I think?”

“Yes, but it was my partner who got hurt.”

“That is one of the ironies of luck. SeÑor Brandon is sober and cautious, but he gets injured when he comes to protect you, who are rash.”

“He’s what you say, but I didn’t know you had met him,” Jake replied.

“I have heard of him; you foreigners are talked about in the cafÉs. They talk much in Santa Brigida; many have nothing else to do. But have you and SeÑor Brandon only been molested once?”

Jake hesitated for a moment. He liked the man and on the whole thought he could be trusted, while he imagined that he was not prompted by idle curiosity but knew something. Besides, Jake was often impulsive and ready, as he said, to back his judgment.

“We were only once actually attacked, but something rather curious happened not long ago.”

“Ah!” said Don Sebastian, “this is interesting, and as I know something of the intrigues that go on in the city it might be to your advantage to tell me about it. There is a quiet wine-shop not far off.”

“Would it be safe to go in?” Jake asked.

“I think so,” his companion answered, smiling.

Jake presently followed him into a small, dimly lighted room, and noted that the landlord came to wait on them with obsequious attention. Two peons were drinking in a corner, but they went out when the landlord made a sign. Jake thought this curious, but Don Sebastian filled his glass and gave him a cigarette.

“Now,” he said, “we have the place to ourselves and you can tell your story.”

Jake related how a stranger had stolen into their shack a few days ago, and Don Sebastian listened attentively.

“You do not think it was one of the peons employed at the dam?” he suggested.

“No,” said Jake. “Anyhow, Payne seemed satisfied it wasn’t.”

“He would probably know them better than you. Do you keep money in the house?”

“Very little. We lock up the money for wages in the pay-office safe. Anyhow, I’m not sure the fellow came to steal.”

“If he did so, one would not imagine that he would be satisfied with blotting-paper,” Don Sebastian agreed. “You said there was some coffee on the table.”

“There was. Payne reckoned the fellow meant to dope it. What do you think?”

“It is possible, if he had ground for being revengeful. Some of the Indians from the mountains are expert poisoners. But why should anybody wish to injure your comrade?”

“I didn’t suggest that he wished to injure Brandon. He might have meant to dope me.”

Don Sebastian smiled. “That is so, but on the whole I do not think it probable. Do you know of anybody whom your friend has harmed?”

Jake decided to tell him about Oliva. He was now convinced that Don Sebastian knew more than he admitted and that his interest was not unfriendly. Besides, there was somehow a hint of authority in the fellow’s thin, dark face. He showed polite attention as Jake narrated the events that had led to Oliva’s dismissal, but the lad imagined that he was telling him nothing he had not already heard.

“The motive may have been revenge, but as SeÑor Brandon was stabbed that ought to satisfy his enemy. Besides, these people are unstable; they do not even indulge in hatred long. Do you know if your comrade has taken any part in political intrigue?”

“It’s most unlikely; he would make a very poor conspirator,” Jake replied.

“Then have you heard of any seÑorita, or perhaps a half-breed girl who has taken his fancy?”

“No,” said Jake. “Dick is not that kind.”

He thought Don Sebastian had been clearing the ground, eliminating possibilities to which he did not attach much weight, and waited with interest for his remarks.

“Well,” said the Spaniard, “I think you and the man, Payne, should watch over your friend, but it might be better if you did not tell him you are doing so or ask him any questions, and I would sooner you did not mention this interview. If, however, anything suspicious happens again, it might be an advantage if you let me know. You can send word to me at the hotel.”

“Not at Kenwardine’s?”

Don Sebastian gave him a quiet glance, but Jake thought it was keenly observant and remembered how, one night when a messenger entered Kenwardine’s patio, Richter, the German, had stood where he obstructed the Spaniard’s view.

“No,” he said, “I should prefer the hotel. Will you promise?”

“I will,” Jake answered impulsively. “However, you seem to suggest that I should leave my partner to grapple with this thing himself and I don’t like that. If he’s up against any danger, I want to butt in. Dick’s no fool, but there are respects in which he’s not very keen. His mind’s fixed on concrete, and when he gets off it his imagination’s sometimes rather weak——”

He stopped, feeling that he must not seem to censure his friend, and Don Sebastian nodded with a twinkle of amusement.

“I think I understand. There are, however, men of simple character and no cunning who are capable of going far and sometimes surprise the friends who do not know them very well. I cannot tell if SeÑor Brandon is one of these, but it is not impossible. After all, it is often the clever man who makes the worst mistakes; and on the whole I imagine it would be wiser to leave your comrade alone.”

He got up and laid his hand on Jake’s arm with a friendly gesture. “Now I will put you on your way, and if you feel puzzled or alarmed in future, you can come to me.”