The New Policeman

Irish teenager J.J. Liddy discovers that time is leaking from his world into Tir na n’Og, the land of the fairies, and when he attempts to stop the leak he finds out a lot about his family history, the music that he loves, and a crime his great-grandfather may or may not have committed.

Artemis Fowls : The Lost Colony

Thousands of years ago, fairies and humans fought a great battle for the magical island of Ireland. When it became clear that they could not win, all of the fairies moved below ground except for the 8th family. Rather than surrender, they used a magical time spell to take their colony out of time and into Limbo. There they have lived for decades, preparing to exact their violent revenge on humans.