IT was a gloomy night. The sun had gone down in a bank of black clouds. The lightning was playing above the western hills, and the thunder was beginning to grumble. The lightning flashed more sharply; a wind swept across the valley; the rain began to patter, then to pour; the lightning leaped flash upon flash out of the inky sky, while closely following every stroke came the cracking, booming thunder. The storm was on in all its fury, driving through the swaying trees and drenching the group of silent wigwams that stood ghost-like within the edge of an aspen grove at the foot of the eastern mountains.