Systematic attacks on the Wells Fargo & Co's diligences are increasing. In order to restore its coat of arms and restore confidence to its customers, the company decides to send a diligence full of passengers and with a large load of gold on the west coast of the United States. For this the Wells Fargo & Co ensures the services of the coach driver Hank Bully and the contest of Lucky Luke that will ensure the escort. Insurmountable mountains, infernal deserts, dreadful roads, bloodthirsty Indians and desperados, such will be the program to connect Denver to San Francisco... But the Wells Fargo & Co always passes!...