The title of this chapter pretty much covers it. Smaug is not at home. This is a lucky break for the company. They are trapped in the tunnel by the back door, as the door has been destroyed, so their only option is to go down to Smaug’s lair and explore.
Of course it isn’t that easy for them to arrive at that conclusion. They are absolutely terrified and, of course, it is up to Bilbo to get them where they need to be. Bilbo goes first. He climbs the great mound of treasure and finds the Arkenstone, the heart of the mountain. He puts it in his pocket, which will be important later. For now, we just know that it is a gem that far exceeds all others and that Thorin really wants it.
After Bilbo’s initial exploration, he convinces the dwarves to come have a look around for themselves. Almost immediately upon seeing the treasure, it “rekindled the fire of their dwarvish hearts.” They are a fickle bunch. They waste no time exploring and pocketing all the treasure they can hold. They also all picked out fine armor and weapons. Even Bilbo, who thought he must look magnificent and absurd at the same time.
Bilbo has to remind them that the dragon could come back at any moment and they should find a way out. Finally, he gets some help. Balin and Thorin remember the halls and passages. They lead the party to the front door. Balin remembers an old lookout station that is secluded and will be a safe place for them to hide for the time being. They make it there and have at least a moment’s calm.
That’s really about it for this chapter. It is a bit of a pause in the action. It does some set up and some character work, but that’s about it. We need to wait until the next chapter to find out what happened to Smaug.