To prevent discovery of the cruel methods he is using in building a Bolivian railway, Gillespie ( Anders Randolf ), a ruthless construction crew foreman, attempts to kill Arthur Wyatt ( Walter Pidgeon ), an Englishman sent to inspect the job. Gillespie's niece, Toni ( Dolores Del Rio ), a half-breed, discovers the plot and saves Wyatt after he has been shot by her uncle's accomplice.