TIA agents Mortadelo and Filemón are called again for a dangerous mission. Tons of cod are being sold to a ridiculously low price in the city, causing an overflow of proportionally thirsty citizens due to the fish's dry, salty nature. Behind this seemingly harmless stunt turns out to be no other than the local Italian mafia, led by godfather Lucrecio Borgio, whom the Supervisor suspects might have more sinister intentions. Soon, Mortadelo and Filemón discover Borgio plans to monopolize the city's water supply, effectively strangling its economy due to the demand created by the cod, and are ordered to stop him.
The story was initially published by parts in the Gran Pulgarcito magazine, continued in the Mortadelo magazine after the former folded down. It is therefore divided into five chapters which were kept when it was re-published as a full album.
Its general plot, or a modernized, James Bond-esque version of it, served as the basis for the second live action movie, Mortadelo y Filemón - Misión: salvar la Tierra, released in 2008. The secret entry to the TIA headquarters was also featured in the first movie in 2003.
The 2007 chapter Venganza cincuentona featured the return of Lucrecio Borgio and his gang, although in a very minor way.
This comic provides examples of:
- Artificial Limbs: Both Mortadelo and Lucrecio Borgio use fake arms to feign hands-up before attacking their opponent with weapons on the real ones.
- Bad Boss:
- True to his nature, the Supervisor threatens agent Floro with death (by writing his name in a list of agents KIA), all with a bright smile, if he doesn't accept to be Disguised in Drag. Even worse, the very next chapter, La máquina del cambiazo, seems to confirm that the Super actually ended up executing Floro at some point for not obeying another order.
- Filemón is also in his worst in this chapter, continually mistreating and punching Mortadelo for actions which should have been his own fault.
- Bad People Abuse Animals:
- Having a guard crocodile is one thing, but it's then revealed that the Borgio household built an "alarm" by gluing the tail of a cat to the floor in front of a door, making the kitty scream in pain every time an intruder steps on it. Even when Aldo comes to believe it was a false alarm, he stills berates the cat for it.
- Subverted later with Mortadelo, theoretically not a bad guy, who force-feeds their dog a whole bone when he sees the dog reacts with disdain to its food. It is then double subverted because it is not a dog, but X-9, a disguised TIA liaison, who later returns the favor.
- Bait-and-Switch: Mortadelo lights up when Filemón says they have got a new car with a rotative engine. The vehicle turns out to be a peddle-powered car, though.
- Bilingual Dialogue: A lot of Borgio's lines are in untranslated Italian, as the Spanish and Italian languages are mutually intelligible due to their closeness in the Romance language tree.
- Bittersweet Ending: Mortadelo and Filemón capture Borgio and his entire gang, but they also end up crushed by rocks, and in the process of closing the case they have caused tons of damage property by causing a deluge on the city.
- Booby Trap: How Mortadelo finally gets rid of the crocodile. He sets up a fake leg of his with a dynamite stick inside, which blows up all the animal's teeth when it bites it.
- Continuity Snarl: As said above, four of the five parts of El caso were published in a different magazine due to the disappearance of the previous. From that point, strangely, the TIA and the Supervisor never appear again on the story, being replaced by the regular police, and the title recovers the piece Agencia de información used by the series before its long chapter phase. It has been suggested that Ibáñez was forced by the second magazine to re-canonize the story as taking place in the pre-TIA old times, back when Mortadelo and Filemón worked as freelance detectives, in the belief that the new TIA format would not be successful.
- Crouching Moron, Hidden Badass: As accustomed, when the occasion calls for it, Mortadelo scores a ton of points against the mafia and end up capturing them with tricks and traps, one by one.
- The Don: Lucrecio Borgio, explicitly a mafioso.
- Double Take:
- Lucrecio nods when Aldo praises the statue he bought for their other room, realizing seconds later that he bought no statue. He hits Aldo, believing him to be drunk or insane.
- Mortadelo and Filemon also take a bit to notice that the suspicious-looking bank janitor spoke to them in Italian.
- Mortadelo digs out food for their dog (and mistreats it a bit) just before realizing they have no dog. It was a disguised TIA agent.
- Failed a Spot Check: Filemón spends hours destroying a brick door to escape a cell... learning too late that Mortadelo had been warning him that the mafiosos had mistakenly left the door unlocked.
- The Ghost: An apparent additional member of Borgio's team is called Petronio, but he never appears on page. Chances are that it is an overlooked usage of a name that got changed in a second draft.
- Giant Squid: After the city is flooded, Mortadelo turns into a giant squid to goad Borgio, hit with with his nightstick and send him to the bottom with a large naval mine.
- Godzilla Threshold: When Mortadelo and Filemón realize Borgio has succeeded at monopolizing water in the city, the former tries a drastic measure: he dresses up like a native American shaman and does the rain dance, which causes a deluge and completely drowns the mafia's plans.
- The Guards Must Be Crazy: The mafiosi who put Mortadelo and Filemón inside a cell forget to lock the door.
- Hoist by His Own Petard:
- In a looooong sequence, Mortadelo puts up a ton of traps in the Borgio house, all of which are activated by Filemón.
- The agents also try to use incendiary glue to blow up a bomb while a mook is carrying it, but they fail to activate it - until the bomb is right where the mafioso wanted it to be and Mortadelo accidentally lights up the glue.
- Mortadelo also accidentally mines their own boat in the flooded city.
- At the very end of the chapter, the agents manage to throw a boulder on Borgio, crushing him - but when the boulder returns, it destroys the rock cliff they were standing on, collapsing it and crushing them as well.
- It Can Think: Turns out Borgio's guard crocodile is smarter and more skillful than it looked. When Filemón tries to cross over it on a wooden plank, the crocodile grabs the plank and turns it into a chute towards its mouth.
- Just Shoot Him: The entire mafia pulls this, as Borgio decides none of their plans will work with Mortadelo and Filemón alive. Predictably, they fail.
- Let's Get Dangerous!: After being clobbered too many times for his incompetence, Aldo finally catches the title agents and holds them in gunpoint. He's only defeated by one of Mortadelo's tricks.
- Literal-Minded:
- Typically, Filemón asks Mortadelo whether he sees guard dogs, and upon his negative answer he is surprised by a guard crocodile that Mortadelo didn't see fit to mention because Filemón asked specifically about dogs.
- Mortadelo's idea of "sitting the head" (a Spanish idiom for "settle down") is donning a bizarre Cephalothorax disguise and sitting on a chair.
- Lock-and-Load Montage: After the mafia and the title agents declare war on each other, they both can be seen doing this with some eccentric weapons. Aldo checks a club equipped with a gun sight, while Mortadelo grabs a slingshot loaded with a hand grenade, and Filemón can also be seen loading bullets in his gun via funnel.
- My Little Panzer: In midst of a fight, Mortadelo suddenly quick-draws and holds Lucrecio on gunpoint, but the latter only laughs because it is visibly a rubber gun. Surprisingly, Mortadelo then shoots him in the face, revealing the gun was actually functional despite being made of rubber (and was loaded with shotgun ammo, nothing less).
- Palate Propping: Attempted with the crocodile, and failing miserably when the animal just breaks the stick.
- Pulling the Rug Out: Mortadelo and Filemón try this on Lucrecio and another mook, but it fails hilariously, as the rug was so cheap that it tears up by the edge they were holding. They also get knocked out against the wall when the momentum makes them fall backwards.
- Right Hand Versus Left Hand: As mentioned above in Hoist by His Own Petard, Mortadelo sets up a lot of traps around Borgio's house... and Filemón, being unaware of their location, manages to activate every single one of them.
- Satchel Switcheroo: How Mortadelo captures one of the mafiosi. He snatches his club and replaces him with a dynamite stick without him realizing, and then dresses up like a cop so the baddie quickly hides the alleged weapon under his shirt. The item then explodes, leaving him knocked out.
- Shout-Out:
- The story is a Whole-Plot Reference to the Anacleto chapter El malvado Vázquez, created by Ibáñez' colleague and close friend Manuel Vázquez (who starred As Himself in the series as the Big Bad, nothing less). Moreover, the cat alarm is a parody of a similar scene in El sobre lacrado, another Anacleto story. Ibáñez inspiring himself on Vázquez was so usual that the latter sometimes poked fun at it in his own works.
- The plot point with the crocodile was taken from André Franquin, as well as the cat disguise used by Mortadelo, which resembles a cat drawn in Franquin's style.
- Borgio combs Aldo's hair before hitting him over the head with his club, just as in the Mexican comedy series Chespirito.
- Swiss-Army Weapon: Filemón has a literal Swiss Army knife which contains, in Hammerspace, a pick and a morning star, along with other 68 tools according to him.
- Unsettling Gender-Reveal: Mortadelo hits on a secretary with long, beautiful hair... only for her to be revealed as a hippie-looking guy. Mortadelo then viciously sets the guy's hair in fire for the confusion.
