Describe Bilbo’s use of another weapon—his intelligence—to find a way into the Lonely Mountain. How does Tolkien insinuate or imply the “answer” to this puzzle before the characters have figured it out? Why do you think he does this?

In Chapter 12, with Gandalf away, Bilbo takes on the role of the leader. Now that they've reached their destination, the dwarves don't know what to do, so it is up to Bilbo to think a head and give them their instructions. The dwarves use their tools, and Bilbo uses his brain to locate the secret door. As the dwarves despair, Bilbo uses his intelligence to remember what Elrond told them about the moon letters, and then he uses his knowledge to decipher the runes.