The B&M Railroad is blocked in its goal of extending the line to the Pacific Ocean when Frank Sayer(J. Gordon Russell), the crooked guardian of Bobbie Van Tyne (Louise Lorraine,) refuses to let the railroad cross Bobbie's ranch land. Railroad detective "Whispering" Smith (Al Ferguson)persuades Jack Venable (Lane Chandler), son of the man who built the line's best train,"The Lightning Express", to give up his wild-party, playboy life to help him investigate the death of Bobbie's father. Using an alias, Jack goes to work for the railroad as a foreman. He and Bobbie fall in love, and she decides to support the railroad. But Sayer goes all out in his attempt to stop construction, so he can acquire the right-of-way, and puts the lives of Jack and Bobbie in constant danger.