I've been reading through Eoin Colfer's Artemis Fowl books thanks to the Disney-Hyperion promotion through Goodreads this year, leading up to the release of the final book in the series -- The Last Guardian -- coming this summer. After reading the fifth book in the series, I was excited for what came next; Artemis was growing up; the series seemed to be taking a different turn; and then we got to one of my least favorite plot devices: time travel.In The Time Paradox, Artemis had returned from Limbo at the end of the previous book to find three years had passed. His mother had given birth to twin sons in his absence, and he decided he had to use fairy magic he had acquired to erase her memory, as well as his father's, so they wouldn't question him too closely about the missing three years. Unfortunately, his mother becomes ill, and Artemis believes it's a magic-related illness he has somehow transferred to her with his ill-gotten magic. He tricks his sprite friend, Holly Short, into coming along with him, going back in time to try to save a single lemur he believes will cure his mother.Colfer employs the predestination paradox theory for his time travel, which always frustrates the hell out of me as a reader. In other words: nothing can be changed. Artemis was always going to go back in time, everything was always going to happen exactly as it did, and nothing will change it. It always makes me feel like I've wasted my time reading a book, and this was no exception.Others who don't have a predisposition against time travel books may find this a much more enjoyable read than I did. I found the plot needlessly convoluted, however, and a disappointment after the fun of the last book.