The Lost Road itself was the result of a deal between Tolkien and C. S. Lewis, where they agreed to an attempt at writing science fiction. Lewis ended up with writing a story about space travel, which would become The Space Trilogy, and Tolkien would try to write something about time travel, but he never completed it. It is just a fragmentary beginning of a tale, including a rough structure and several intriguing chunks of narrative, including four entire chapters dealing with modern England and Númenor, from which the entire story as it should have been can be glimpsed. The scheme was of time-travel by means of 'vision' or being mentally inserted into what had been, so as to actually re-experience that which had happened. In this way the tale links first to Saxon England of Alfred the Great, then to the LombardAlboin of St. Benedict's time, the Baltic Sea in Old Norse days, Ireland at the time of the Tuatha Dé's coming (600 years after the Flood), prehistoric North in the Ice Age, a 'Galdor story' of Third Age Middle-earth, and finally the Fall of Gil-galad, before recounting the prime legend of the Downfall of Númenor/Atlantis and the Bending of the World. It explores the theme of a 'straight road' into the West, now only in memory because the world is round.