“And you seem to have made a prisoner of the same fellow yourself,” Reade retorted.

“As an officer of the Mexican Army, senor, that is my privilege,” came the lieutenant’s response.  “As to your right, however, to arrest and hold a Mexican citizen, there may be some question.  I shall have to satisfy myself on this point before I can release you.”

“Why, I’ll be wholly frank with you,” Tom Reade offered.  “This fellow, Gato, is a rascal whom I had occasion to thrash.  In revenge for the humiliation he has given me to understand that he would kill me.  Last night he held us up at the point of his rifle.  Our servant, Nicolas, threw a stone that bowled Gato over.  Then, for our own safety, we tied him up and brought him with us.”

“Why was it necessary to your safety, senor, since you had the fellow’s rifle and his ammunition?  You see, I have gained this much from your friend.”

“Why was it necessary?” Tom repeated, wonderingly.  “Why, Lieutenant, do you feel that we should have turned a deadly enemy loose?”

“But you had no right to arrest him, senor.”

“Nor did we arrest him in the sense that you mean, Lieutenant.  All we did was to render Gato helpless and bring him along with us until we should have passed out of the bit of country in which he might have been dangerous to our safety.”

“How could he be dangerous when you had his weapon?” the lieutenant demanded, argumentatively.

“Why, he had other men out with him.  How long would it have taken Gato to find his men and bring them down upon us—­three or four guns against one?”

“But did you see his other men at any time in the night?”

“No,” Tom admitted.

“Senor, you have made a grave mistake in arresting and holding the man, Gato.  You had no right to do so.”

“Why, in our own country,” Tom protested, “any one may arrest a man who is committing a crime.  In our own case we very likely would have lost our lives to bandits if we had not tied Gato and brought him with us.”

“Had you tied him and left him behind it might have been different,” explained the lieutenant.  “But what you did, Senor Reade, was to make an actual arrest, and this you, as an American, had no right to do.  Therefore, I shall hold you until this matter has been further inquired into.”

It was a bad plight, and there seemed to be no simple way out of it.  The young chief engineer began to see that, innocently, and wholly for the purpose of self-protection, he very likely had infringed upon the kinds of rights that foreigners in Mexico do not possess.

“All right, Lieutenant,” sighed Tom.  “I suppose we shall have to go along with you.  Where are you taking us?”

“That will have to be decided,” said the officer.  “Nowhere for the presents my men are tired and need rest.  We will not humiliate you, Senor Reade, by placing you in irons, but I will ask your word of honor that you won’t attempt to escape from us.”