Prince Lazlo of Ambrasia is fascinated with the Texas Rangers and picks Laredo as the site to sign a treaty with Aguacaldo. His half sister Helena and consort Karl see this as their perfect opportunity to kill Lazlo, which they attempt with poison and a hired gun. Chad Cooper is a dead ringer for the Prince and Captain Parmalee decides they should switch identities for the Prince's safety. Reese believes the Prince to be Chad dressed up until the Prince passes out from drinking a shot of red-eye. The ruse is eventually figured out by Helena and Karl whose hired gunman goads the Price dressed as Chad into a gunfight. Chad is able to substitute for the Prince at the last moment and scares the gunman off with his fancy gun-handling. The gunman kidnaps the Prince and demands more money from Helena. Reese and Joe rescue the Prince and return him in time to sign the treaty and expose Helena and Karl.