Joan Lane is hand-cuffed to a police detective on her way to prison when the train derails and she escapes. The fugitive is taken in and hidden by Mrs. Mortimer, a once-wealthy socialite who has been wiped out by the stock market crash. She is using pretty Joan as bait to lure bachelor Ronald Stanhope into a trap. She plans to steal a priceless diamond he brings aboard the Transcontinental Limited. But her scheme grows complicated when Joan and Ronald...