Santo in The Diabolical Axe aka Santo en el hacha diabólica continues the idea of a Santo legacy that was first introduced in Santo vs. the King of Crime, via flashback scenes we visit colonial times and meet an ordinary man (whose face is never shown) who is magically transformed into Santo, el Enmascarado de Plata, complete with his 20th-century wrestling outfit!
The film also caused excitement by including an unmasked Santo scene. The real Santo (Rodolfo Guzmán Huerta) did not film that scene though instead an uncredited actor was used and only 3/4 of his face is visible as he kisses actress Bety González.
The film begins in 1603: a procession of monks places the body of El Santo in a tomb. After they leave, a man wearing a black hood suddenly appears and swears vengeance on Santo, even if it takes centuries to achieve. The setting shifts to the present: Santo is wrestling Lobo Negro, but the axeman mysteriously appears in the ring and tries to kill the hero, tossing the other wrestler and the referee aside. Police bullets don’t harm the hooded man, but he just as suddenly vanishes. A reporter scoffs, assuming it was a publicity trick, but the axe-wielding stranger does not show up in his photographs.
Santo leaves with Alicia, his blonde girlfriend. They park for a while to talk. Santo says he likes Alicia, but he has the feeling that somewhere there is a woman that he’s always been in love with. Alicia asks to see Santo’s face, he unmasks and they kiss.
Santo is asleep, when the axeman appears and tries to kill him, but a woman’s scream, coming from out of nowhere, saves the masked hero. Santo takes the axe–which didn’t disappear this time when the Black Hood vanished–to his friend, Dr. Zanoni. Under magnification, the axe proves to have the date 1603 and a skull engraved on it. Santo’s mask, which was passed down to him from his father, has a tiny occult design on it as well (the word “Abracadabra” in a triangle). Zanoni tells him that Abraca was a famous magician in the 17th century; as he speaks, a woman mysteriously appears. She is Isabel de Arango, who had earlier saved Santo’s life by screaming; if Santo defeats the axeman, their love can live again. Then she disappears. Santo is clueless: “I’ve forgotten everything.”
Zanoni and Santo connect themselves to a machine which will allow them to visit the past. Back in 1603, a man, beseeches “Arimán” for help. He desires Isabel de Arango, but she is in love with another. At a costume ball, Isabel’s suitor is wearing a silver mask, and the evil would-be boyfriend is wearing a black one. Outside, they have a swordfight which ends with the villain suffering a wound. He staggers to the secret dungeon where he has his altar to Arimán. A voice tells him that he will have to give up his soul in exchange for Satanic assistance. The man agrees, and is converted into the Black Hood (Fernando Osés’ face is very briefly seen in this sequence: why his face is otherwise hidden in the pre-Hood scenes is inexplicable, unless it was easier to dub his dialogue that way, or unless there was some idea of linking him with the pre-Santo character, whose face is also never shown).
Arimán says he can’t make Isabel fall in love with the Black Hood, but he does give the Hood a trunk full of jewels and gold. The Hood will have power and wealth unless he is defeated and unmasked. He kidnaps Isabel and chains her up in his dungeon. Isabel’s suitor can’t locate her. Despairing, he goes to see magician Abraca, who lives in a cave. Abraca tells him that “Isabel is no longer of this world,” but changes the man into Santo so he can fight evil. Back in town, Santo and the Inquisition capture the Black Hood, who is burned at the stake, but turns into a bat and flies away. Santo, despondent, enters a monastery to live out his days.
Back in 1964, Zanoni suggests that Santo try to locate Isabel’s resting place, by checking out existing colonial-era houses. The Black Hood pops in for another attempt on Santo’s life; after watching the fight with interest for a bit, Zanoni steps in front of the axe, saving Santo’s life. As he dies, he changes into the bearded magician Abraca.
Santo’s next wrestling opponent is possessed by the spirit of the Black Hood, and turns into a dirty fighter. The crowd gets mad, tossing pieces of trash into the ring. After Santo wins, his opponent is still booed by the fans.
Santo is back together with Alicia, and they go to their usual parking spot. He says she could be in danger, so they can’t see each other for a while. She goes home and gets ready for bed, then senses something wrong and calls Santo on the phone; Santo hears her scream. He goes to her apartment and finds her dead. Santo tells the police: “I swear the killer will pay for his crime.”
After some research, Santo locates the house where he believes Isabel’s body is. There is a long sequence in which he wanders around the house. Abraca’s spirit appears and warns him of danger; a secret door opens, and Santo finds the Black Hood’s secret dungeon.
Santo and the Black Hood fight, but Santo picks up a big torch-holder and strikes the axeman, then pulls off the man’s hood. The villain turns into a bat and is pinned to the wall with a spike. Isabel returns to her human form and says she can move on to her eternal rest: Santo will “continue fighting for goodness and justice.” The room’s furnishings vanish. Santo is left alone in the empty room.