Tolkien would, towards the end of his life, devote his last writings to the issue of Glorfindel and some related topics, as detailed in "The Peoples of Middle-earth". In "The Return of the Shadow", Christopher Tolkien stated that some time after the publication of "The Lord of the Rings", his father "gave a great deal of thought to the matter of Glorfindel" in the book, and decided that it was a "somewhat random use" of a name from that would probably have been changed, had it been noticed sooner. The issue lay in Tolkien's original conception of the spirits of dead Elves as being re-embodied in their old bodies after a Purgatory-like period in the Halls of Mandos in Valinor, the home of Tolkien's "gods", the Valar and Maiar, where Elves previously lived before (re)migrating to Middle-earth. After being re-embodied, previously dead Elves stay in Valinor permanently.