When county treasurer Dr. Raymond Pratt loses the money in his care to political robbers, he disappears after leaving a note for his friend Tom Hammond saying that he will not return until he has replaced all of the money. Hammond replenishes the treasury out of his own pocket and dies in the poorhouse, without Pratt knowing that his disgrace was never made public. Years later, Hammond's nephew, Dr. Thomas Rawn, is sent West to investigate a mysterious disease called the Blue Death on the Quien Sabe ranch, owned by Pratt, who now poses as Hank Weaver. Thomas falls in love with Weaver's daughter Jenny but she resists his affection, thinking that he is a spy for a rival ranch, until he saves her from the Blue Death. In the end, Weaver discovers that he is not in disgrace and accepts an important post in Washington where Jenny and Thomas realize their love for each other.