The Ildatch is a book of black magic featured in The Wishsong of Shannara . This book emerged in the Age of Faerie, long before the rise of humankind. Its story was told to Brin Ohmsford by the Druid Allanon. Allanon also told Brin that she was the only one who could destroy it. When Brin came to destroy the Ildatch, she, too, was subverted by it and was transformed. Her brother, Jair Ohmsford, then found her in a tower in the middle of the Maelmord. There, after a confrontation between subverted sister and determined brother, Brin was able to destroy it with her wishsong.