How does Smaug react when he discovers the theft in the cup? How do the adventurers escape from him?

Bilbo manages to steal a cup and hurriedly exits but Smaug awakens and begins to rage. The cowardly dwarves decide that Bilbo must re-enter the cave and somehow alleviate the situation as Smaug is now set upon destroying the countryside and has already prevented the company from escaping because he has destroyed their ponies.

Bilbo has returned to the cave and though he is on his guard, he riddles and discusses various topics with Smaug. He escapes with his life and as Smaug begins a rampage on the countryside, Thorin sees his imminent kingdom approaching. For once, Smaug is gone, the prophesied reclamation of old dwarf treasure will come to pass.