It's an almost perfectly accurate analogy.

So, JRR Tolkien wrote The Hobbit for his school age children. It's a novel that is designed to be read to children one chapter a night as a series of bedtime stories. It tells the tale of Bilbo Baggins, a hobbit enjoying his quiet life in the suburbs, being swept along on a quest along with some dwarves and a wizard to slay a dragon that stole some treasure. Along the way a series of adventures ensue, one of which involves Bilbo finding a handy magic ring that turns anyone who wears it invisible.

Several years later, Tolkien decided to write an epic trilogy of novels that tell a much more mature story in the same setting. See it turns out that the fun invisibility ring Bilbo found is an all powerful evil artifact hand crafted by the setting's equivalent of Lucifer as part of a jewelry-based ploy to take over the world in the name of evil, and the only place the ring can be destroyed is in the fires of the volcano in which it was forged in the first place. It falls on Bilbo's nephew Frodo Baggins to carry the ring from the suburbs to this volcano to destroy the ring and defeat evil once and for all.

Tolkien made it sound cooler than I just did.