Armand and Marie survive in the streets until charitable (and wealthy) scientist Pierre Marcel takes Armand in after a botched robbery. Marie, a fiery Apache, swears revenge on Marcel for taking her lover away from her.
Joe Ryan, a veteran train engineer, is demoted to a flagman position after a disastrous crash-- one caused by his cowardly and opportunistic partner. Though Ryan's failing eyesight is named as the cause of the crash, he's undeterred as he designs an automatic braking invention.
