|Episode 219: The Mouth of the Snake|
|Air Date||8 April 1984|
|Written by|| Robert Foster|
Episode 218: A Good Knight's Work
Episode 220: Let it Be Me
David Dalton........Robert Colbert
Joanna St. John........Joanna Pettet
Eduardo O'Brian........Pedro Armendariz Jr.
Apollonia Kotero (credited as Patty Kotero)........Tiara D'Arcy
Michael goes to Calexico on an investigation for Joanna St. John, whose ex-husband, attorney Arthur Abrams, has been murdered at the Mexican border. Abrams was investigating the smuggling of illegal aliens into the country. When Michael and Joanna check out the site, they find the operation was smuggling more than immigrants when pieces of pottery are found with flecks of gold. Heading back to Joanna's motel, the two find an intruder who makes an amazing acrobatic getaway.
Michael learns the man is David Dalton, a federal investigator working secretly for the Justice Department. Dalton is after Eduardo O'Brian, an Irish-Mexican crimelord who Dalton believes is behind Abram's murder. Dalton is hard to catch, but once Michael finds him, he convinces him they are on the same side and should work together. Michael and K.I.T.T. conduct the legwork of the investigation while Dalton stays close to Joanna who decides to infiltrate O'Brien's birthday party at a beach house estate owned by Elton Mathews. Mathews has been supplying the vehicles and equipment for a mysterious digging operation only known as "Boca Culebra" (a.k.a Mouth of the Snake). As KITT creates a disturbance, Michael hitches a ride aboard a truck and finds statues with gold bricks inside. Dalton learns O'Brien is using the gold to purchase a cargo plane, but the reason still eludes him.
Michael and Dalton investigate further and discover a warehouse filled with rockets. Michael and KITT soon learn the rockets are for a semi truck with a mobile launcher hidden in the trailer and the duo barely escape its attack.
Joanna becomes better acquainted with O'Brien who quickly becomes infatuated with her. He invites her aboard his yacht where she manages to steal the combination to his safe. Dalton later sneaks aboard and breaks into the safe where he finds plans for advanced weapon systems. O'Brien eventually figures out he's been duped when he finds the combination in Joanna's waste basket, however he doesn't immediately let on that he knows.
Meanwhile, Michael follows Mathew's trucks to the dig site discovering a cave "the mouth" and a secret tunnel "the snake" which leads to a military weapons depot. The pieces come together as O'Brien plans to use the rockets to attack the base while his men raid the depot vaults for the experimental weapons. The plane will arrive and transport the weapons out of the country. Now Michael and Dalton must stop O'Brien and Mathews who have kidnapped Joanna and set out on their operation to attack the depot.
- "Mouth of the Snake" served as a backdoor pilot for a short lived series entitled Code of Vengeance, revolving around the former Vietnam vet David Dalton.
- Although this episode's "officialy" titled 'Mouth Of The Snake', it is also known as 'All That Glitters', the story's original working title.