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.
- Always a Bigger Fish: An anaconda saves Haddock from a crocodile 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.
- Badass Moustache: Manolo.
- Bald of Evil: Sponsz.
- 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.
- Big Damn Heroes: It doesn't get much bigger or damner than showing up to call off an execution in a giant carnival float.
- The Chessmaster: Sponsz prepares both a perfect trap for Tintin and tries to arrange his deaths 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.
- 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.
- Dragon-in-Chief: Sponsz.
- 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 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!"
- 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.
- Egopolis: Tapioca has renamed the capital of San Theodoros "Tapiocapolis". When Alcazar takes over, he changes the name again, to "Alcazarpolis".
- Face–Heel 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 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."
- It's Always Mardi Gras in New Orleans: 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.
- 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...).
- La Résistance: The Picaros.
- 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.
- The Man Behind the Man: Sponsz to Tapioca.
- 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.
- 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.
- Not So Different: Alcazar and Tapioca.
- 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 Vilified / The Revolution Will Not Be Civilized: Hard to tell which trope this falls into. Though the Picaros are on Tintin's side, they're not portrayed as much more that 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.
- Shout-Out: The carnival includes revellers wearing Mickey Mouse, Donald Duck, Snoopy, Zorro, Groucho Marx costumes, as well as, quite surprisingly, one dressed as Astérix — 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've you understood. This is a reference to Charles De Gaulle, who in 1959 said to the Algerian people wanting independence: People of Algeria, I've you understood.
- Snap Back: One of the newspaper clipping 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.
- Take That: According to some, Peggy Alcazar may actually be a caricature of Hergé's ex-wife Germaine.
- 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.
- 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!"