Jack, the foreman's assistant, loves Marian, the foreman's daughter. Nothing exciting ever happens in the out-of-the-way construction camp. He is warned by an old blacksmith in the camp that something may happen any time. Later a stranger arrives in the camp and wins the attention of Marian. The stranger seems to care for no one but the little child of the blacksmith, and seems to be a man of mystery. One day a girl arrives whom the stranger has deserted. She is shot when she tries to kill him to avenge a wrong. A posse led by Jack starts after the stranger and leads through various parts of the camp. The stranger is cornered at one end of the trestle on the electric construction railroad. Here he starts an electric engine across as his pursuers are after him. They are about to be swept off to the rocks below. Just then the blacksmith's child, who has been hiding on the work train, cries out. The stranger sees her going to her death. As the only way to stop the engine he pulls down the trolley wire, stopping the engine, but resulting in his own death.