Bilbo Baggins, a respectable, well-to-do hobbit, lives comfortably in his hobbit-hole until the day the wandering wizard Gandalf chooses him to take part in an adventure from which he may never return.

It is well known that J.R.R. Tolkien published The Hobbit in 1937 and The Lord of the Rings in 1954-5. What may be less known is that he continued to write about Middle-earth in the decades that followed, right up until the years before his death in 1973. For him, Middle-earth was part of an entire world to be explored, and the writings in The Nature of Middle-earth reveal the journeys that he took as he sought to better understand his unique creation....