A military patrol carrying pay to Fort Gila is attacked, the soldiers are brutally murdered and scalped. Evidence points to an Indian ambush, but the fact that the money is missing makes Tex and Carson suspicious, and they begin to investigate...
Willer and Carson are drawn into a great intrigue, connected to the assassination of Abraham Lincoln, the public disclosure of which could lead to major upheavals in the highest circles of government.
Major Granger steals the famous "jewel of Akbar" from the Indian Raja and flees to the USA. On his deathbed, he hands over the jewel to Captain Jones. At the request of New Orleans Sheriff Nat MacKenneth, Tex and Carson try to recover the jewel...