While on a tour to San Theodoros, Bianca Castafiore, her troupe and the Thom(p)sons are imprisoned by General Tapioca on the false charges of being involved in a conspiracy to overthrow him along with Tintin, Haddock and Calculus. Haddock and Calculus decide to travel to San Theodoros to clear their names, while Tintin initially refuses, correctly suspecting it to be a trap. Not wanting to leave his friends alone, Tintin does follow them after a few days.
In San Theodoros they discover that Castafiore's imprisonment was orchestrated by their old enemy Colonel Sponsz, who used his influence to help Tapioca rise to power, as an elaborate trap. They find that the only way to save their friends from imprisonment and execution is to help General Alcazar and his rebels, the titular Picaros, overthrow Tapioca once more.
This was the last Tintin story completed and published by Hergé before his death in 1983. The unfinished draft of what would've been the follow up— and the Grand Finale to the series— was posthumously published in 1986.
- Adaptation Distillation: The encounter with Ridgewell and the Arumbayas is removed from the Animated Adaptation.
- Always a Bigger Fish: An anaconda saves Haddock from a caiman at one point.
- And Here He Comes Now: Captain Haddock is saying to Professor Calculus that Tintin was wise not to come along with them to the Gilded Cage they're being held at:Calculus: I can see our hosts have a true sense of hospitality. That's what I just said to him... And he entirely agrees with me.
Haddock: WHO agrees with you? And about WHAT?!
Calculus: Exactly, and what's more, he'll tell you so himself!
Tintin: Buenos dias, Captain!
- Argentina Is Nazi Land: Or San Theodoros Is Iron Guard Land, since Sponsz is now a political advisor from Borduria. The helmets of Tapioca's soldiers are of the German Stahlhelm pattern, but that was Truth in Television for a number of South American countries at the time.
- Banana Republic: The trope is lampshaded as the Castafiore Conspirators are supposedly in league with the International Banana Corporation.
- Beard of Evil: Sponsz has grown an evil-looking goatee since The Calculus Affair.
- Being Watched: Tintin arrives at the expensive hotel where Captain Haddock is staying and points out the various hidden microphones in his Gilded Cage. He also points at the mirror and says it might be a double-sided mirror with a camera on the other side. Cue Colonel Sponsz watching Tintin on a monitor, pointing directly at him. "He's clever, that boy."
- Beneath Notice: The Jolly Follies' costumes are ridiculously garish, but they fit right in at the San Theodoros Carnival. The Picaros wear the costumes to sneak into San Theodoros's capital and impress General Tapioca enough that he invites them into the presidential palace.
- Big Damn Heroes: It doesn't get much bigger or damner than showing up to call off an execution in a giant carnival float bristling with revolutionaries.
- Bookends: The first picture of San Theodoros as the protagonists arrive there by plane at the beginning shows policemen patrolling in a shantytown with a sign that reads "VIVA TAPIOCA". The last picture of San Theodoros as the protagonists leave the country at the end shows the same policemen in new uniforms patrolling the same shantytown, with a sign that reads "VIVA ALCAZAR". It drives home how Tapioca and Alcazar are Not So Different and nothing will really change.
- Call-Back: The fair-weather nature of the San Theodoran military from The Broken Ear once again rears its head upon Alcazar's successful coup de main, with Tapioca's guards joyfully shouting "Long live General Alcazar!" and "Shoot Tapioca!" even as they still hold their hands up, with Colonel Alvarez saluting Alcazar, offering him his congratulations, and asking him whether he'd like Tapioca shot at once.
- The Chessmaster: Sponsz prepares a perfect trap for Tintin and tries to arrange his death in such a manner that no one will be able to pin it on him.
- Comically Missing the Point: "We didn't get here a minute late, did we?" "I don't know, my watch has stopped."
- Covers Always Lie: Well, not really — the cover's depiction of Tintin, Haddock and Calculus fleeing into the jungle away from a Mesoamerican pyramid is perfectly accurate. But this refers to an extremely fleeting scene in the book, and suggests that the story will be another foray into pre-Columbian culture in South America, in the manner of Prisoners of the Sun. In fact the story is otherwise contemporary in tone and is much more focused on political and military concerns. A depiction of General Tapioca's carnival, for instance, would have been a more telling cover.
- Cruel Mercy: Tapioca begs not to be spared, commiserating with Alcazar over the idealism of the younger generation.Tapioca: Have mercy, don't have mercy on me!
- Cut Phone Lines: After their successful coup, the protagonists try to call the prison to cancel the execution, but keep getting the wrong number and have to race there in person. In the animated version, there's simply no tone: As Colonel Alvarez suggests, the Picaros must have cut the phone line during the assault to avoid Tapioca calling in reinforcements.
- Damsel in Distress: Castafiore and her maid Irma, though Castafiore doesn't exactly act too "distressed".
- Distressed Dude: Thomson, Thompson and Igor Wagner the pianist.
- Dying Declaration of Love: As they stand before the firing squad, Thompson asks "Can you perhaps think of some famous last words?", to which Thomson responds "Er... What about, 'Kiss me, Thompson'... Will that do?" However, this is just a throwaway joke by the English translator based on Horatio Nelson's penultimate words after he was shot during the Battle of Trafalgar. In the French version he just goes with "San Theodorians, I have understood you!", while in the Animated Adaptation, he simply says "goodbye".
- Eagleland: Peggy is a type 2. Hergé apparently based her on a KKK virago he once saw on TV.
- Easy Amnesia: Haddock briefly loses his memory, allowing us to learn his name: Archibald.
- Egopolis: Tapioca has renamed Los Dopicos, the capital of San Theodoros, "Tapiocapolis". When Alcazar takes over, he changes the name again, to "Alcazaropolis".
- FaceHeel Turn: Pablo has gone back to being evil since The Broken Ear.
- Fate Worse than Death: Tapioca regards being exiled instead of executed as this.Tapioca: "Have mercy, don't have mercy on me!"
- Full-Circle Revolution: It's subtly implied in the last panel that the living conditions in San Theodoros under Alcazar's rule are just as bad as under Tapioca.
- Gilded Cage: Sponsz keeps Haddock and Calculus in one.
- The Glomp: Castafiore hugs Haddock after he releases her from prison.
- Henpecked Husband: General Alcazar to Peggy, destroying the last remnants of his Dashing Hispanic image.
- I Know You're Watching Me: Tintin arrives at the hotel where Captain Haddock is staying and points out the various hidden microphones. He also points at the mirror and says it might be a two-way mirror with a camera on the other side. Cue Colonel Sponsz watching Tintin on a monitor, pointing directly at him. "He's no fool, that boy."
- In My Language, That Sounds Like...:Pablo: "Tomorrow, Colonel Alvarez will take you on a trip to Hotuatabotl to see an ancient pyramid."
- It's Always Spring: The original (serialised) version had green trees and what seemed to be summer in Belgium, despite the fact that the climax of the story takes place during Carnival. This was pointed out to Hergé, who corrected it in future editions.
- Jumped at the Call: Averted! Tintin initially refuses to accompany Haddock and Calculus to San Theodoros, rightly suspecting it to be a trap. Played straight in the Animated Adaptation, however.
- Kangaroo Court: Tapioca holds one for Bianca Castafiore and the Thompsons. You almost end up pitying the man in charge (Castafiore starts singing, the Thompsons protest that their mustaches are not satires but that they've had them since childhood...).
- Later Installment Weirdness: Tintin refuses to jump at the call for the only time in the series. He also ditches his iconic Outdated Outfit of plus-fours for normal full-length trousers.
- La Résistance: The Picaros, though it would be more accurate to describe them as The Remnant of the previous regime.
- Loud of War: Castafiore interrupts her Kangaroo Court trial by saying she laughs at the prosecutor's allegations, yes, she laughs, Ah! She laughs, to see herself so beautiful in this mirror! Just before We Are Experiencing Technical Difficulties, "SILENCE!", "CLEAR THE ROOM!" and "TO ARMS!" are among the shouts heard in the room.
- Missed Him by That Much: Thompson and Thomson are sharing a friendly drink with the officer in charge of their firing squad, making it look like the events of "The Broken Ear" will repeat. But they're led out to be executed just as the radio starts to announce the change of government.
- Nailed to the Wagon: Haddock finds that all alcohol has taken on an absolutely repulsive flavour to him only at the beginning of the story. The reason is that Calculus slipped him a drug he invented to cure alcoholism that makes alcohol taste disgusting. The same drug is later used to sober up all the members of Alcazar's resistance movement.
- Not So Different: Alcazar and Tapioca, whose respective regimes are ultimately not that much different from each other. They even share a moment of commiseration once it's clear Alcazar is not going to have Tapioca executed because of his promise to Tintin.
- Pity the Kidnapper: Bianca Castafiore is a very demanding prisoner, sending a guard back wearing half the pasta as it was not cooked al dente.
- The Revolution Will Not Be Civilized: Though the Picaros are on Tintin's side, they're not portrayed as much more than drunk mercenaries. The protagonists mostly just assist Alcazar in order to save their friends, not because they particularly care about San Theodoros and the final panel of the book implies that in the end nothing has changed except the uniform of the soldiers.
- Scenery Based Societal Barometer: Played for cynical laughs - the story begins with San Theodoros under the control of General Tapioca, complete with an establishing shot of two police officers patrolling an impoverished shantytown, both of them dressed in the crisp uniforms of Tapioca's regime. At the end of the story, after Tintin has won the day for General Alcazar and unseated Tapioca, we return to the same shantytown... which is exactly the same except that the sign has a different name on it and the two police officers are now dressed in the more rumpled uniforms of Alcazar's Picaros - indicating just how little the country has actually changed.
- The carnival includes revellers wearing Mickey Mouse, Donald Duck, Snoopy, Zorro, and Groucho Marx costumes, as well as, quite surprisingly, one dressed as Asterix — a nod to the Friendly Rivalry between Herge and the creators of the Gaul, Uderzo & Goscinny.
- The costumes of the Swinging Extravaganzas are based on those of the Gilles of Binche, which are festival characters from a local feast in Binche, known all over Belgium.
- In the original version Thompson and Thomson think of any last words and suggest: People of San Theodoros, I have understood you. This is a reference to Charles de Gaulle, who in 1959 said to the Algerian people wanting independence: People of Algeria, I have understood you.
- Snap Back: One of the newspaper clippings seen at the end of The Red Sea Sharks stated that Alcazar was back in power in San Theodoros. Apparently, Tapioca overthrew Alcazar again between albums, though since we saw them commit multiple coups against each other in The Broken Ear in just one day, this isn't really all that surprising.
- This Is My Name on Foreign: Colonel Sponsz goes by the Hispanicized name Esponja in San Theodoros.
- Thou Shalt Not Kill: Tintin only agrees to present Alcazar with his plan of overthrowing Tapioca on the condition that he doesn't have anyone executed. Both Alcazar and Tapioca himself find this idea repulsive.
- Unreveal Angle: Colonel Esponja, only seen from behind at first.
- Your Television Hates You: Haddock is not amused by the ads for Loch Lomond whiskey he keeps seeing after being Nailed to the Wagon. "It's a plot!"