“That’s right, Frank. But how can it benefit us?”

“Well, look here. Suppose we appeared before the Inca and his Council as a delegation from the fortress and demanded Prince Huaca’s release on pain of working our magic on the Inca and all his forces. Then we’d give them a demonstration. Your father has a little pointed beard. He could make up to look like a magician. He’d make a few passes, utter some words in English—anything would confound them, as English is unknown to them—and then Pedro would pull out his teeth, Carlos would pluck out his eye, and Don Ernesto would scalp himself. Wouldn’t that just give them fits? Wouldn’t it just——”

But Jack’s bewildered expression had given way to one of mirth, uncontrollable mirth, and he laughed until he was weak, leaning back against the wall, his hands pressed to his aching sides. Frank, too, yielded to merriment, expostulating between spasms of laughter:

“You promised not to laugh, Jack. You promised.”

The sound of their laughter reached Don Ernesto and Mr. Hampton, and they looked inquiringly toward its source; then, as the boys continued to go off into fresh gales of mirth, arose from the couch and approached them.

“What’s the joke, boys? Let us in on it,” said Mr. Hampton, smiling.

“Oh, I can’t, Dad. I can’t speak. Ask Frank.”

Jack was so weak he could hardly support himself. The ludicrous idea propounded by his friend, coming on top of his nervous strain, had induced a species of hysteria.

The two older men grinned in sympathy with the boys, although in the dark as to the cause of their laughter.

“Some boyish joke, I suppose,” said Mr. Hampton, and was about to turn away, but Jack recovered himself sufficiently to lay a detaining hand on his arm.