As a result of taking the treasure of the Indios Blancos (from the previous adventure "Il mistero dell’idolo d’oro"), Mexico invades the southern part of Texas. Tex joins the regular American forces who manage to stop the Mexicans and the conflict turns into a guerilla war. Tex is tasked with uncovering a Mexican spy.
This is where he finds a suspicious magician: Steve Dickart accompanied by his sister.
