"Unfinished Tales" is a collection of stories and essays by J.R.R. Tolkien, compiled and edited by his son Christopher Tolkien. The book includes tales from Middle-earth that were left incomplete or unpublished during the author's lifetime, as well as background information and notes on the creation of his fictional world. The stories range from the early days of Middle-earth to the events leading up to "The Lord of the Rings," providing fans with a deeper understanding of Tolkien's complex and intricate mythology.