The Mystery at Little Creek

You are an agent in the Pinkerton Detective Agency and you have been assigned to investigate the disappearance of a Pony Express rider. The rider had been delivering mail to the distant and remote town of Little Creek, Arizona, but he never returned. The telegraph office in Little Creek is not responding, which is unsettling but not unusual. The agency wants you to get to the bottom of this mystery, but they cannot spare another agent, so you are on your own. This is a horror mystery set in the American Old West.