Morgan Starr is involved in a cattle deal planned along with a treaty between Mexico and the United State to be signed at a small village in Mexico. The treaty is to be signed by U.S. Senator Mills and Mexican governor Delgado. Starr and Trampas agree to travels to the site in advance to check the security as the Senator does not want to send a military delegation. They find the village quiet and peaceful with a few Americans visiting. Trampas leaves to report all is well for the signing the next day. After he leaves Starr discovers some 7th Cavalry troops there with a fake story. He along with a female bar owner and a padre are taken captive by a group run by an old friend Cleve Mason who was a U.S. Marshal at Cimarron hired to assassinate the two men who are to sign the agreement. The group has brought a Gatling gun in a casket to use in the assassination. Starr works with the padre to undermine the plot and salvage the agreement while the female bartender renews a relationship with one of the assassins.
—Anonymous