The Hobbit: The Desolation of Smaug2013

Thorin:
I know my father came to see you before the Battle of Moria. What did you say to him?

Gandalf:
I urged him to march upon Erebor, to rally the seven armies of the dwarves. To destroy the dragon and take back the Lonely Mountain, and I would say the same to you. Take back your homeland.

Thorin:
This is no chance meeting is it, Gandalf?

Gandalf:
No, it is not. The Lonely Mountain troubles me, Thorin. That dragon has sat there long enough, sooner or later darker minds will turn towards Erebor. I ran into some unsavory characters whilst traveling along the Greenway. They mistook me for a vagabond.

Thorin:
I imagine they regretted that.

Gandalf:
One of them was carrying a message. [he unrolls the message and slides it across the table to Thorin] It is Black Speech. [Thorin looks at Gandalf with unease] A promise of payment.

Thorin:
For what?

Gandalf:
Your head. Someone wants you dead. Thorin, you can wait no longer. You are the heir to the throne of Durin. Unite the armies of the dwarves, together you have the might and power to retake Erebor. Summon a meeting of the seven dwarf families, demand they stand by their oath.

Thorin:
The seven armies swore that oath to the one who wields the King's jewel, the Arkenstone. It is the only thing that will unite them, and in case you have forgotten, that jewel was stolen by Smaug.

[Gandalf notices the two men that had been watching Thorin earlier get up and leave the bar]

Gandalf:
What if I were to help you reclaim it?

Thorin:
How? The Arkenstone lies half a world away, buried beneath the feet of a fire breathing dragon.

Gandalf:
Yes, it does. Which is why we're going to need a burglar.

[scenes changes to twelve months later, with Bilbo peeking out of a mountain ledge]