This makes no sense. LotR is a novel, with (depending how you count them) two to five or more protagonists (Frodo, Sam, Aragorn, Gandalf, Theoden, Merry, Pippin, maybe Faramir and/or Boromir).
Each of those characters had - in the fiction - a choice about what to do, where to go, etc. But of course the author has them make choices that will drive the story he wants to tell.
If, in your game, a player had their PC pick up on one of those adventure hooks, and exciting things happened as a result, presumably a story could be written that retold those exciting events. It may not be as long or intricate as LotR, but it would still - presumably - involve a sequence of events that follows from the choices made by the PC, including the choice to "bite" on the hook.