Washington White bounded along like a rubber ball. He came to the plateau that overlooked the sheltered camp of the oil hunter. As the darkness retreated across the valley, the derrick and the shanties belonging to Phineas Roebach's outfit appeared.
Suddenly several gunshots rang out in succession, and the sounds startled the boys and Andy. Wild cries likewise arose from the valley. The commotion was at the camp.
"The professor is in danger!" cried Andy Sudds, and began to run.
His first leap carried him twenty feet; his second took him over a fallen tree-trunk six feet through.
"By Joshua!" ejaculated the startled hunter. "I've got springs in my shoes; ain't I?"
"What can it mean, Jack?" panted Mark, as the boys hurried on, side by side.
Jack Darrow had no answer to make. He was as amazed as his companions, and perhaps a little frightened as well.
They hurried after Andy and Wash; but the latter was far ahead. There was a second volley of gunshots and at that moment Wash came to the verge of the steep descent to the camp.
He beheld some half dozen Indians—all swart, lank, fierce-looking bucks—just at the point of rushing the oil borer's hut.
It was no time for explanations, nor for hesitancy. Wash, like the others behind him, believed that the Indians were making an attack upon their master, and the first thought of all was that Professor Henderson was with the oil man, and in peril.