“But—­but,” he stammered, “what was his object?  Why did those people scheme to get me?”

“Why!  Money, no doubt; you are wealthy, are you not?”

“Yes, to an extent.  I inherited property, but I had no considerable sum with me that day; not more than a few hundred dollars.”

“As I told you, Mr. Cavendish, I do not know all the details, but I think these men—­one of whom is a lawyer—­planned to gain possession of your fortune, possibly by means of a forged will; and, in order to accomplish this, it was necessary to get you out of the way.  It looks as though they were afraid to resort to actual murder, but ready enough to take any other desperate chance.  Do you see what I mean?”

“They will rob me!  While holding me here a prisoner they propose robbing me through the courts?”

“That is undoubtedly their object, but, I happen to know, it has not yet been fully accomplished.  If either of us can make escape from this place we shall be in time to foil them completely.”

“But how,” he questioned, still confused and with only the one thought dominating his mind, “could they hope to obtain possession of my fortune unless I was dead?”

“They are prepared to prove you dead.  I believed so myself.  The only way to convince the courts otherwise will be your appearance in person.  After they once get full possession of the money they do not care what becomes of you.  Living or dead, you can never get it back again.”

He sank down on the bench and buried his face in his hands, thoroughly unnerved.  The girl looked at him a moment in silence, then touched his shoulder.

“Look here, Mr. Cavendish,” she said firmly, “there is no use losing your nerve.  Surely there must be some way of getting out of here.  For one, I am going to try.”

He looked up at her, but with no gleam of hope in his eyes.

“I have tried,” he replied despondently, “but it is no use.  We are buried alive.”

“Yet there must be ways out,” she insisted.  “The air in that passage was perfectly pure; do you know anything about it?”

“Yes; it leads to the top of the cliff, up a steep flight of steps.  But it is impossible to reach the passage, and since these Mexicans came I have reason to believe they keep a guard.”

“They were not here, then, at first?”

“Only for a few days; before that two rough-looking fellows, but Americans, were all I saw.  Now they have gone, and Mexicans have taken their places—­they are worse than the others.  Do you know what it means?”

“Only partially.  I have overheard some talk.  It seems this is a rendezvous for a band of outlaws headed by one known as Pasqual Mendez.  I have not seen their leader; but his lieutenant had charge of me.”

“Miss Donovan,” he said with gravity, “we are in the hands of desperate men.  We will have to take desperate measures to outwit them, and we will have to make desperate breaks to obtain our freedom.”