When his mother catches a sudden and strange disease, fourteen-year-old Artemis Fowl seeks the help of his fairy friends. When Captain Holly Short takes a look, she has no other option but to declare a case of Spelltropy, a fairy disease that was thought to have been rid of years ago, but has apparently been spread to humans. The only cure for Spelltropy is the brain fluid of the silky sifaka, a lemur drove to extinction eight years ago, by ten-year-old Artemis Fowl himself. Now, in order to save his mother, Artemis the elder must travel back in time to prevent himself from selling the lemur to the odious Dr. Kronski, president of the Extinctionists. But after saving the world from megalomaniac pixies and power-crazed demons, has Artemis Fowl met his match- himself? Along the way, Artemis may also run into some old friends- and some top archenemies.