After his last run-in with the fairies, Artemis Fowl's mind was wiped of memories of the world belowground and any goodness grudgingly learned is now gone with the young genius reverting to his criminal lifestyle.

Artemis's mother has contracted a deadly disease -- and the only cure lies in the brain fluid of African lemurs. Unfortunately, Artemis himself was responsible for making the lemurs extinct five years ago. Now he must enlist the aid of his fairy friends to travel back in time and save them. Not only that, but he must face his deadliest foe yet...his younger self.

Artemis has committed his entire fortune to a project he believes will save the planet and its inhabitants, both human and fairy. Can it be true? Has goodness taken hold of the world's greatest teenage criminal mastermind? Captain Holly Short is unconvinced, and discovers that Artemis is suffering from Atlantis Complex, a psychosis common among guilt-ridden fairies - not humans - and most likely triggered by Artemis's dabbling with fairy magic. Symptoms...