Half an hour after bedtime, three boys might have been seen to slip out of a window of the dormitory to the ground. It was dark, the stars twinkling sharply in the clear sky. Swiftly they sped away from the building, along the edge of the campus and two hundred yards beyond, until they came to a great tall tree, whose abundant branches and foliage hugged close and tapering to the trunk. There they stopped, sat down, with the tree between themselves and the school, and whispered excitedly to each other.
Ten minutes later another dark form emerged from another window of the dormitory and took a similar course. He carried a bundle under one arm. Hardly had he left the shadow of the school buildings and the bordering trees when another youth slipped from the same window and followed him.
The three forms under the tree hugged close to the ground as the boy with the bundle passed within twenty feet of them. Presently the fifth boy reached the tree and the three forms under it stood erect.
“Come on,” beckoned the last youth, and all four started in pursuit of the one ahead.
Presently the latter heard a footstep behind and threw a startled look backward. With a half-choked cry of astonishment, he broke into a run and fairly flew along the road that led toward Mummy Cañon.
CHAPTER XVII
EXPLORING THE CAVE
“Hal! Oh, Hal! Stop! This is Pickles.”
Hal stopped almost as suddenly as he had started to run. He recognized the cautious cry of his friend and waited for the four to overtake him.
“What you kids up to?” he inquired, after scanning the faces of the quartet. “I told you not to come, Pickles.”
“We’re not going to run away with you,” he replied. “We’re just going to walk a ways and then go back.”