Apparently with sudden remorse at his impetuosity, he turned to the doctor.

"I beg your pardon," he exclaimed. "I _did_ forget myself. But to me, men like that are intolerable."

Vicenti was not to be mollified.

"Then you had better avoid their presence," he said angrily.

With an impatient gesture he motioned the two Americans into the corridor, and in distress approached the prisoner.

"I apologize, sir," he said, "for having subjected you to such an incident."

But General Rojas made no answer. To his surprise, Vicenti found that the old man was suffering from the scene even more keenly than he had feared. Like one suddenly bereft of strength, General Rojas had sunk into his chair. His bloodless, delicate hands trembled upon the table.

Great tears crept down his white, wrinkled face. In the two years through which the young doctor had watched his patient he had never before seen in his eyes the strange, mad light that now shone there.

To the medical man, it meant only that the end was nearer than he had supposed. Shocked and grieved, the doctor made a movement to withdraw.

"I am deeply sorry," he murmured.

General Rojas raised his head. With an effort he drew over his face its customary, deathlike mask.

"It is nothing!" he exclaimed. "What is one more insult, what is one more degradation, when I know that my end is near!" He raised his voice; it was strangely vigorous, youthful, jubilant; it carried through the open bars to the far end of the corridor. "What does anything matter," he cried, "when I know--that the end is near!" His head sunk upon the table. To hide his tears, the General buried his face in his hands.

Outside, in the darkness, Peter clutched Roddy by the hand, and for an instant crushed it in his own.

"Do you hear?" he whispered. "He is answering you."

"Yes," stammered Roddy. The excitement or the dampness of the prison had set him shivering, and with the back of his hand he wiped the cold moisture from his forehead. He laughed mirthlessly. "Yes," he answered, "he understood me. And now, we've _got_ to make good!"

That afternoon when the carriages of the aristocracy of Porto Cabello were solemnly circling the Plaza, Roddy came upon McKildrick, seated on one of the stone benches, observing the parade of local wealth and fashion with eyes that missed nothing and told nothing. McKildrick was a fine type of the self-taught American. He possessed a thorough knowledge of his profession, executive skill, the gift of handling men, and the added glory of having "worked his way up." He was tall, lean, thin-lipped, between thirty and forty years of age. During business hours he spoke only to give an order or to put a question.

Out of working hours, in his manner to his a.s.sistants and workmen, he was genially democratic. He had, apparently, a dread of being alone, and was seldom seen without one of the younger engineers at his elbow.

With them he was considered a cynic, the reason given for his cynicism being that "the Chief" had tried to "take a fall out of matrimony,"

and had come out of it a woman-hater. Officially he was Roddy's superior, but it never was possible for any one in the pay of the F.

C. C. to forget that Roddy was the son of his father. Even McKildrick, in certain ways, acknowledged it. One way was, in their leisure moments, not to seek out Roddy, but to wait for the younger man to make advances. On this occasion, after for a brief moment contemplating McKildrick severely, Roddy, with an impatient exclamation, as though dismissing doubts and misgivings, sat down beside him.

"McKildrick," he began impetuously, "I want to ask you an impertinent question. It concerns your moral character."

McKildrick grinned appreciatively.

"We court investigation," he said.

"Under what pressure to the square inch," demanded Roddy, "would a secret confided to you be liable to burst its boiler?"

"I've never," returned the engineer, "had an accident of that kind."

"Good!" exclaimed Roddy. "Then suppose I said to you, 'McKildrick, I know where there's buried treasure, but I don't know how to get it out.' You _would_ know. Now, if I led you to the buried treasure, would you, as an expert engineer, tell me how to dig it out, and then could you forget you'd given that advice and that you'd ever heard of the treasure?"

For a moment McKildrick considered this hypothetical case. Then he asked: "Which bank are you thinking of opening?"

Roddy rose abruptly.

"I'll show you," he exclaimed.

That Roddy was acting, in spite of secret misgivings, was so evident, that McKildrick good-naturedly demurred.

"Better not tell me anything," he protested, "that you'll be sorry for when you're sober."

Roddy shook his head, and, not until they had left the suburbs and the last fisherman's hut behind them and were on the open coast, did he again refer to the subject of their walk. Then he exclaimed suddenly; "And I forgot to mention that if Father finds out you advised me you will probably lose your job."

McKildrick halted in his tracks.

"It's a pity," he agreed, "that you forgot to mention that. As a rule, when I give expert advice I get a fat check for it."

"And what's more," continued Roddy, "if Alvarez finds it out you'll go to jail."

"Your piquant narrative interests me strangely," said McKildrick.

"What else happens to me?"

"But, of course," explained Roddy rea.s.suringly, "you'll tell them you didn't know what you were doing."

"How about _your_ telling me what we are doing?" suggested the engineer.

"From this point," was Roddy's only reply, "you crawl on your hands and knees, or some one may see you."

The engineer bent his tall figure and, following in Roddy's trail, disappeared into the laurel bushes.

"Why shouldn't they see me?" he called.

"One looks so silly on his hands and knees," Roddy suggested.

For ten minutes, except for the rustle of the bushes, they pushed their way in silence, and then Roddy scrambled over the fallen wall of the fort, and pointed down at the entrance to the tunnel.

"The problem is," he said, "to remove these slabs from that staircase, and leave it in such shape that no one who is foolish enough to climb up here could see that they had been disturbed."

"Do you really think," demanded McKildrick, smiling sceptically, "that there _is_ buried treasure under these stones?"

"Yes," answered Roddy anxiously, "a _kind_ of buried treasure."

Cautiously McKildrick raised his head, and, as though to establish his bearings, surveyed the landscape. To the north he saw the city; to the east, a quarter of a mile away, the fortress, separated from the mainland by a stretch of water; and to the south, the wild mesquite bushes and laurel through which they had just come, stretching to the coast.

"Is this a serious proposition?" he asked.

"It's a matter of life and death," Roddy answered.

McKildrick seated himself on the flight of stone steps, and for some time, in silence, studied them critically. He drove the heel of his boot against the cement, and, with his eyes, tested the resistance of the rusty bars of iron.

"With a couple of men and crowbars, and a pinch of dynamite that wouldn't make a noise," he said at last, "I could open that in an hour."

"Could you put it back again?" asked Roddy.