The introduction of the people of Lake Town places humans in Tolkien’s hierarchy of good and evil races. The human denizens of Lake Town are quite cautious when it comes to confronting the dragon. When the company sets off for the mountain, the humans refuse to go near it, leaving Bilbo and the dwarves to fend for themselves. Though they are concerned most about themselves, the people of Lake Town cannot really be blamed for fearing Smaug—they are convinced that he is invincible. Though Tolkien here emphasizes human fallibility and fear, he portrays humans as generally good creatures.
With the riddle of the secret door, Tolkien draws his readers into the story by presenting a confusing puzzle that we attempt to solve before the characters do. Tolkien employs this device often—we have already seen it in the riddle game between Bilbo and Gollum. At the mountain, we have an even greater advantage over the characters. The company has passed through many dangers since their last night in Rivendell, where Elrond interpreted the moon runes on the map for them, explaining that the door could open only on Durin’s Day, one of the last days of autumn. Except for Bilbo, they have quite forgotten the message about “when the thrush knocks. . . .”
We are more likely to have the message fresh in mind, however, especially since the narrator notes several times in Chapter 11 that “Autumn was now crawling towards winter.” The difference between the reader’s knowledge and the characters’ ignorance, a situation of dramatic irony, adds to the suspense and urgency of the moment Bilbo figures out the secret of the door. Tolkien builds tension toward the descent into the mountain and the characters’ confrontation with Smaug by playing upon our desire for the characters to realize what we already know.