Ten thousand years ago, humans and fairies fought a great battle. When the fairies realized they'd never win, they moved their civilization underground and hid. All the families agreed, except the demons.

The demons planned to lift themselves out of time until they were ready to wage war on the humans once more. But the spell went wrong, and they were catapulted into Limbo. Now the spell's deterioration is accelerating and the demon materializations are erupting. Even the fairy scientists cannot predict the next one.

But someone can. Artemis Fowl, teenage criminal mastermind, has solved temporal equations that no human can. So when a confused and frightened demon pops up in a Sicilian theatre, Artemis is there to meet him. Unfortunately, a second mysterious party has also solved the equations and has managed to abduct the demon.

Once again, Artemis will pair up with his old comrade Captain Holly Short, to track down the missing demon, before the spell dissolves completely and the lost demon colony returns violently to Earth.