The townsmen row Bilbo and the dwarves up the lake for three days. They disembark near the Lonely Mountain, and the townsmen row away in fear. The travelers set out through Desolation of the Dragon, a waste land, toward the Mountain. They gaze out on the ruined and abandoned town of Dale. They camp near the mountain and unexpectedly find its secret door, but cannot open it. Over a period of days, the dwarves use all kinds of tools to try to open the door, but have no success.
Thorin comments that autumn is almost at an end; the next day, Bilbo hears a thrush cracking a snail on a stone near the door and is suddenly reminded of Elrond's story about the keyhole being revealed on Durin's Day. Bilbo and the dwarves wait for the setting sun to reveal the hidden keyhole, and Thorin opens the door with the key Gandalf gave him with the map.
This chapter represents the fulfillment of Elrond's prophecy and so lends a sense of destiny to Bilbo and the dwarves' journey. Thorin's claim to the treasure in the mountain gains legitimacy as the door opens with the key he has been given. The magic of Durin's Day has a similarity to the ancient pagan beliefs surrounding the equinox and solstice.