La caja de los diez cerrojos ("The Ten-Lock Strongbox") is a 1971 comic from the Spanish series Mortadelo y Filemón, and the eighth long adventure in the series.
A multi-millionaire oil magnate decides that his entire fortune will be inherited by the T.I.A. upon his death, but he apparently had a strange sense of humor, because he chose to invest all that money in making an indestructible, impossible-to-pick strongbox with ten locks, storing a mysterious object worth millions, and then had each key buried in a different part of the world.
Naturally, the Supervisor cannot let this stroke of fortune go, and tasks Mortadelo and Filemón with following the list of places where the keys were buried and recover them all.
- All for Nothing: When the agents finally find all the keys and they and the Supervisor finally open the strongbox, it turns out to be a gigantic jack-in-the-box, so they angrily throw it into the sea, thinking it to be a practical joke - only for the jack to be hiding a ginormous diamond.
- Bad Boss: The agents are forced to pay for their own travel plans to the different parts of the world where the keys are hidden. The only time he gives them anything, it's barely enough to cover a couple of taxi rides - and it's actually a fake bill.
- Epic Fail:
- One of the keys is in the middle of the sea, so Filemón orders Mortadelo to trace the location on a map. After many measurements and calculations, Mortadelo proudly points he has found the coordinates - and Filemón answers he found them in the center of Ciudad Real
. - Another key is said to be on the Moon, and the agents attempt to get a ride on a rocket. It's a failure... and then Filemón realizes that he didn't read the paper completely, because the Moon in the list turns out to be a bar.
- One of the keys is in the middle of the sea, so Filemón orders Mortadelo to trace the location on a map. After many measurements and calculations, Mortadelo proudly points he has found the coordinates - and Filemón answers he found them in the center of Ciudad Real
- Gotta Catch 'Em All: The agents must retrieve the ten keys that will open the title strongbox.
- Real Vehicle Reveal: A staple of Ibáñez's works. When the agents are traveling to Africa, they appear to be riding on a plane - only for the plane to pass by and reveal that the duo is riding a paper plane.
- Refuge in Audacity:
- Mortadelo manages to get close to the Saturn rocket by claiming he needs to install a horn.
- The last key is hidden in the T.I.A. building. Taped up to the bottom of the strongbox.
- Right for the Wrong Reasons: Played for Laughs. In the Moon chapter, Mortadelo takes a huge wheel and claims he needs to change one of the rocket's wheels. The guard realizes he's an imposter - because Mortadelo did not have a jack.
- Shout-Out: The gag of walking on hippos while thinking they are stepstones comes from Spirou & Fantasio.
