The Lord of the Rings (LotR for short) is an epic high fantasy novel about the heroism of Frodo Baggins and other characters, written by English philologist JRR Tolkien. The story began as a sequel to Tolkien's earlier, less complex children's fantasy novel The Hobbit (1937), but eventually developed into a much larger work. It was written in stages between 1937 and 1949, much of it during World War II. Although generally known to readers as a trilogy, Tolkien initially intended it as one volume of a two volume set along with The Silmarillion; however, the publisher decided to omit the second volume and instead released The Lord of the Rings in 1954-55 as three separate books rather than one, for economic reasons. It has since been reprinted countless times and translated into many languages, becoming one of the most popular and influential works in 20th-century literature.
Early in the 21st century, The Lord of the Rings film trilogy consisting of three live action fantasy epic films: The Fellowship of the Ring (2001), The Two Towers (2002), and The Return of the King (2003) were released. Along with the films and the books, the whole entity is called the 'LotR legendarium'.
For more information on the legendarium, see One Wiki to Rule them All.
Lord of the Rings in Supervolcano
Kelly Birnbaum was studying the volcanic eruption at Ranger Lake in Yellowstone National Park when a second volcano began erupting at Coffee Pot Springs at the other end of the park. Larry Skrtel managed to arrange a pair of helicopters to evacuate the party of geologists in the morning. It was difficult to tell when the sun rose, due to all the ash. Kelly was reminded of Sauron's evil smokes and fumes from The Lord of the Rings hiding the sun. When the helicopters arrived, she was reminded of the arrival of the eagles to save Frodo and Sam at Mount Doom.
Later that morning, after the geologists landed in Bert Mooney Airport in Butte, Montana, the Yellowstone Supervolcano erupted. The cloud in the southeast swelled and swelled. It reminded Kelly of the blast from Mount Doom when the One Ring went into the fire in The Return of the King.
Months later, after the Supervolcano stopped major eruptions, Kelly and her colleagues went in a Learjet 40,000 feet over the new caldera to examine it both visually and with various instruments. She was again reminded of the lava in The Return of the King. It wasn't as impressive as the movie both because she wasn't at eye level and it wasn't CGI but real life. She wondered what would have happened to Sauron's creation if it was dropped into the pit and suspected it would be gone for good. Kelly realized that if Mount Doom happened to be under the supervolcano when it erupted then it would be gone too.
Lord of the Rings in The Valley-Westside War
The Lord of the Rings continued to be popular in the home timeline, so much so that the Mendoza family used the word "Mellon" (which translates as friend in the fictitious Elven language in LotR) as the vocal password to their Crosstime Traffic safe-room. They used it because of a memorable scene in the first film (The Fellowship of the Ring) where the Fellowship were trapped outside the door into Moria until Gandalf used the word to magically open the door.
Since the film trilogy came out well after the break-point of an alternate devastated by nuclear war in the 1960s, the Mendozas thought it very secure. However, the books had been published before the divergence and had been very popular when the nuclear war had broken out and continued to be so. Surviving copies of The Lord of the Rings were cherished by the people struggling to rebuild something of the devastated world, and were passed on from generation to generation and regularly read by parents to their children. Dan thought of this when confronted by the sealed door and used the word "Mellon" to successfully open it. If that hadn't worked, he would have used "Open, sesame" next.
Moreover, "Frodo", the name of Tolkien's protagonist, came to be used as a male first name in this alternate. Liz Mendoza was reminded of this again when the Mendozas crossed from The Valley to Burbank and dealt with a customs man named Frodo.