Sharky, a rival road agent, plots to spoil a trial run to be made on Helen's road that will win a mail contract. He opens a waste valve on the tank of the engine, and, when nearing Lone Point, the water tank runs dry. Helen comes to the rescue by mounting the new gasoline speeder and starting off with the mail for the end of the run. The plotters open a drawbridge which she must cross, but Helen outwits them by enlisting the aid of a track gang, crosses the bridge and, after driving the speeder over a crossing under the very nose of an express train, she reaches the end of the run in time to secure the contract.