“Give it to me, Pierre,” said Frank; “Marmion don’t like to be fed by strangers.”

The Ranchero kept on as if he were not aware that he had been spoken to; and his conduct went a long way in confirming the new suspicions that had suddenly sprung up in Frank’s mind.

“Uncle,” said he, that evening, after supper, as he joined Mr. Winters and Archie, who had seated themselves on the porch to enjoy the cool breeze of evening, “how long do you intend to keep that new Ranchero?”

“As long as he will stay,” replied Mr. Winters.  “He is one of the most faithful men I ever had, and he is quite as skillful in his business as either Carlos or Dick.”

“He is a mean man for all that,” said Frank; “he tried to poison Marmion, to-day.”

“I don’t blame him,” said Archie; “a meaner, uglier dog I never saw”—­

“Now, Archie,” interrupted Frank, “I like the dog; and even if I didn’t, I would keep him because he is a present.”

“How do you know that Pierre tried to poison him?” asked Mr. Winters.

“Why, he was holding a piece of meat out to the dog, and when I came up he walked off in a great hurry,” replied Frank, who, when he came to state the case, found that it was not quite so strong against the Ranchero as he had at first supposed.

“He may have done all that, and still be innocent of any desire to injure your favorite.  Marmion doesn’t like him, and, no doubt, Pierre is trying his best to make friends with him.  I’ll insure your dog’s life for a quarter.”

Frank was far from being satisfied.  Somehow, he did not like the scowl he had often seen on Pierre’s face.  He was certain that the Ranchero had intended to harm Marmion; but why?  Not simply because he hated the dog, but for the reason that the animal was in his way.  This was the view Frank took of the case; and, believing that Pierre was there for no good, he resolved to keep a close watch on all his movements.

A day or two after that, Mr. Winters and Archie set out on horseback for San Diego, the former to collect the money for a drove of horses he had sold there, before his departure for the East, and Archie to explore the city.  Frank, hourly expecting his two friends, Johnny Harris and Dick Thomas, who had promised to spend a week with him, remained at home, with the housekeeper and two of the Rancheros, one of whom was Pierre, for company.  Dick and Bob, and the rest of the herdsmen, were off somewhere, attending to the stock.

Frank, being left to himself, tried various plans for his amusement.  He read a few pages in half a dozen different books, took a short gallop over the prairie, shot a brace of quails for his dinner; all the while keeping a bright lookout for his expected visitors, who, however, did not make their appearance.  About noon, he was gratified by hearing the sound of a horse’s hoofs in the court.  He ran out, expecting to welcome Johnny and Dick, but, to his disappointment, encountered a stranger, who reined up his horse at the door, and inquired: