Santo in The Treasure of Moctezuma aka Santo en el tesoro de Moctezuma is the sequel to Santo in Operation 67, in this film the Hong Kong-based international criminal organization from Operación 67 is still in business, but they have a new plan: through research done by a renegade archeologist, the secret location of Emperor Moctezuma’s hidden treasure has been uncovered. However, the map is on the base of a small stone carving of the “plumed coyote,” located in a Mexico City museum; furthermore, the key to deciphering the map is on microfilm that was secreted in Ruth Taylor’s emerald ring, which she gave to Jorge Rubio before she died, at the end of the first film.
Interpol has gotten wind of this scheme, and Santo is alerted. An agent code-named “Flor de Loto” (Lotus Flower) will contact him. As they prepare to participate in a wrestling match, Santo informs his partner Jorge of this. “Is she beautiful?” Jorge asks. “I don’t know,” Santo replies brusquely. “Remember that your amorous adventures have caused us dangers and difficulties.” “If love doesn’t cause dangers and difficulties, what fun is it?” Jorge asks. As they leave the dressing room, Jorge is distracted by an attractive brunette, and has to be dragged away by Santo.
Jorge and Santo enter the ring, and Jorge once again spots the brunette, now sucking on her finger and winking at Jorge! “Get serious,” Santo says, “the match is about to begin.” Mid-way thru the match, the young woman gets up and leaves. She goes to Jorge’s apartment and conducts an intensive search for the ring. Santo and Jorge win, of course.
Meanwhile, members of the organization are stealing the figure of the “plumed coyote” from a museum, using a gas which “freezes” the security guards in place. During their getaway, the crooks run over two motorcycle cops who try to stop them for speeding.
Jorge comes home to find the brunette sitting on his bed. She offers to buy the ring from him, but he’s interested in something else. As they clinch, Jorge is struck from behind by two members of the gang who have quietly entered. They find the ring on a chain around Jorge’s neck, and are preparing to kill him when Santo bursts in. Jorge awakes and tackles the brunette, leaving Santo to handle the two henchmen. The three spies are finally subdued, but before the police can arrive, the brunette detaches one of her earrings and tosses it across the room: it explodes, causing a bright flash and thick smoke, through which they make their escape.
Santo gets a phone call from “Flor de Loto,” asking him to meet her at the Aztec pyramids the next morning. He pulls up in his silver Jaguar, and spots a tiny figure on top of one of the massive stone monuments. However, after he climbs the steps to the top, he sees it is just a dummy–but a dummy loaded with explosives, and he narrowly escapes death when it blows up. Then the two thugs from Jorge’s apartment reappear. After a battle, one spy falls off the pyramid and the other, frightened, says “I’ll talk, Santo!” However, his accomplices drive by the pyramid in their car, and fill him full of lead.
Interpol scientist Cardona gives Santo and Jorge miniature TV transmitters that they wear on their lapels. He explains that the camera not only shows what is in front of it, it also shows the person wearing the camera! “I’ll explain how it works, later,” he promises. Santo, as the senior member of the duo, also gets a miniature bomb to wear around his neck on a string.
A dapper Asian gentleman named Li Chan shows up with a briefcase full of money and offers to buy the emerald ring. Jorge agrees, and hands over a box, which proves to contain one of those springy “snakes” that pops out when the box is opened. The furious Li Chan says “You will hear from us soon.”
Jorge leaves and bumps into a beautiful blonde named Estela. He says “You’re under arrest: you’re a highly dangerous woman, because of your beauty.” They make a date for dinner, and clinch. Santo has been observing all of this via Jorge’s TV camera, a bemused look on his face. That night, Estela and Jorge swim in Jorge’s pool and kiss underwater. Santo is still watching on TV. The next day, Jorge shows up whistling “Solamente una vez,” enthusiastic about his new romance. “I saw it all on TV,” Santo informs him. “All?” Jorge asks. “Up to the underwater scene. Then I turned it off,” Santo replies. Jorge starts to work out, doing curls with a large barbell. “With so much weight, you’ll wind up competing for Mr. Universe,” Santo remarks. “But to be a wrestling champion you need different exercises.” Unfortunately for wrestling fans, Santo doesn’t explain what these would be, and the scene ends.
Jorge and Estela visit bullfighter Manuel Capetillo, who is getting ready for a corrida de toros. He dedicates the bull to Estela. However, Jorge spots two sinister types in the stands. After a chase through the bowels of the plaza de toros, Jorge is cornered on a catwalk over a pen in which a surly bull is waiting. The thugs prepare to toss him in, but Santo shows up and it is one of the spies that falls in and is gored and trampled.
At the wrestling arena that night, Santo is pitted against a fat guy with a crew cut called “Oso” (Bear). One of the spectators keeps yelling “I want to see blood!” and an old lady cheers for Santo. Meanwhile two beautiful twins come in; one makes eyes at Jorge and the other watches Santo wrestle. After the match, Santo–in a good sequence–is nearly run down by car after car in the parking garage. He ducks down a hallway and grabs one of his pursuers– but it’s one of the twins! Jorge and the other twin are back at his apartment, watching Santo and her sister. This is an amusing sequence and the actress playing the twins is very attractive, but they’re never seen again.
Meanwhile, Dr. Cardona has been examining Jorge’s ring. He locates the microfilm but is strangled by intruders. With this information in their hands, the organization manages to locate the entrance to Moctezuma’s treasure vault. Using heavy equipment, the vault is opened, and the gang discovers a hoard of gold, jewels, and other valuable objects. Suki says they will take as much as they can, load it on a ship that is waiting off the coast, and sail to San Francisco to make the final split.
Santo and Jorge find Cardona’s body. He had left them a message on a tape recorder, where he alludes to the location of the treasure, the ship, and San Francisco. They go to the treasure site and find only remnants of the Aztec riches. Since Acapulco is the nearest port where a ship would leave for San Francisco, they fly there.
In the harbour is a small warship, with Suki and his henchmen on board. Santo and Jorge buzz the ship in their light plane, but are shot down by anti-aircraft fire. Parachuting into the ocean, the duo is attacked by gang members in a speedboat. Santo uses his necklace-bomb to blow it up, but now sharks start to appear! In the nick of time, Estela shows up in a cabin cruiser. She is agent Flor de Loto. But they can’t make another attempt on the warship, since it might sink and then Moctezuma’s treasure would be lost. Instead, they’ll have to go to San Francisco and confront the gang there.
They go to the gang’s headquarters in San Francisco’s Chinatown. The leader of the organization has just arrived from Hong Kong, and he is admiring the loot when Santo, Jorge and Estela burst in, shooting. Estela is shot and wounded; Jorge shoots and kills the leader, and then more Interpol agents arrive to mop up. Estela, mortally wounded, says “Did you love me a little, Jorge?” before she dies. Jorge, who for the second film in a row has had a woman die in his arms, leaves glumly with Santo. The end.