"But we'll get away some time, won't we?" she gasped.

He shook his head.

"The chances are slim," he replied grimly.

"Then what good is our signal-fire?" she persisted.

"Not much good," he admitted frankly.

Her heart sank. Her face paled, and her lips trembled as she asked:

"Don't you think it'll be seen sooner or later? Ships must pass by here some time."

He shrugged his shoulders.

"Even if they do, they may not see the fire. If a ship passes near this island it would be a great distance away. It would never occur to them to look here for signals. Besides, very few vessels do pass. A ship may not sight our signal for a year, maybe five years, perhaps never. You remember Alexander Selkirk—Robinson Crusoe. He was twenty-eight years on Tobago island—in complete solitude."

Grace gave a low moan of distress.