Detta är " Eternity Code " av Eoin Colfer.
Most humans don't know about them, mostly because of the IT specialist named Foaly. The Centaurs' technology, and therefore the technology of the fairies, is about a century ahead of ours. Anyway, one more character must not be forgotten: Mulch Diggums. This hairy lad is a dwarf with a wide range of abilities including so-called gas explosions, which are more or less massive farts, and extremely sensitive hair that can pick up vibration, and even sense danger. So much for the characters. Why don't we start with the actual content of the book now.
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With Spiro in possession of the Cube, the fairy folk is in great danger, so Artemis asks his fairy friends for help. Luckily young Artemis has locked the cube with an unbreakable code, an eternity code. The time you require to break this code is said in the name, but with Spiro's possibilities quite a bit less.