A shot came from the ledge, and Ned reached for the button which would start the motors going.
"You've only a minute to decide," he said. "I've come a long way to find you. If you reject this chance you won't get another."
"Well," Lyman cried, stepping up to the seat, very shaky as to nerves and pale as death, "I may as well die from a fall as from a bullet or a knife. If Collins is coming back with the officers, I'll have to do something."
The instant he was in his seat, Ned threw the leather straps about his legs and wrists and buckled them tight. Lyman shivered with fright.
"I thought so!" he cried, mistaking Ned's motives. "This is only another trick!"
The wheels bumped for an instant over the inequalities of the surface, the machine rocked lightly, then the planes lifted into the air, the propellers running like mad. A few ineffectual shots came from the men who were running down from the ledge. Ned saw Jimmie and Jackson chasing Collins out of the valley, heard their shots, and then, in a few moments, saw them at the mouth of the tunnel.
In five minutes more the Nelson was out of all danger, purring through the darkness like a contented cat. Lyman sat moodily in his harness, saying not a word, but fully convinced that this was only another trick of his enemies. Directly the boy slowed the motors down so as to make conversation possible.
"Well," he said, turning on one of the electric bulbs so as to see the face of his passenger, "what do you think of the Nelson? Peach, isn't she?"
"Where are you taking me?" was the only reply to the question.
"That is for you to say. We are not very far from Sicuani, Peru, and from there you can secure transportation back to Asuncion—if you think it safe to go there, under the circumstances. About a hundred miles to the north is Cuzco. You can go there and prepare for your visit to Asuncion if you care to. Then, over here in Bolivia, is Sucre. It might be well for you to go there. Anyway, it is up to you."