Prologue: During the preparations for the birthday party at the beginning of The Lord of the Rings: The Fellowship of the Ring, the elderly Bilbo Baggins (Ian Holm) is writing a memoir. It began long ago in a land far away to the east, the like of which you will not find in the world today.
There was the city of Dale. Its markets known far and wide, full of the bounties of vine and vale. Peaceful, and prosperous. For this city lay before the doors of the greatest kingdom in Middle-earth: Erebor. Stronghold of Thror, King under the Mountain, mightiest of the dwarf lords.
Thror ruled with utter surety, never doubting his house would endure, for his line lay secure in the lives of his son and grandson. Erebor, built deep within the mountain itself, the beauty of this fortress city was legend.
Its wealth lay in the earth, in precious gems hewed from rock, and in great seams of gold, running like rivers through stone. The skill of the dwarves was unequaled, fashioning objects of great beauty out of diamond, emerald, ruby, and sapphire. Ever they delved deeper, down into the dark.
And that is where they found it. The heart of the mountain. The Arkenstone. Thror named it the King’s Jewel. He took it as a sign, a sign that his his right to rule was divine. All would pay homage to him, even the great Elvenking, Thranduil. As the great wealth of the dwarves grew, their store of goodwill ran thin. No one knows exactly what began the rift. The elves say the dwarves stole their treasure.
The dwarves tell another tale. They say the elf king refused to give them their rightful pay. It is sad how old alliances can be broken. How friendships between people can be lost. And for what? Slowly, the days turned sour, and the watchful nights closed in. Thror’s love of gold had grown too fierce. A sickness had begun to grow within him; it was a sickness of the mind. And where sickness thrives, bad things will follow.
The first they heard was a noise like a hurricane coming down from the north. The pines on the mountain creaked and cracked in a hot, dry wind. It was a fire drake from the north. Smaug had come. Such wanton death was dealt that day, for this city of men was nothing to Smaug; his eye was set on another prize.
For dragons covet gold, with a dark and fierce desire. Smaug destroys much of Dale and makes short work of Erebor's defenses, despite the brave and canny leadership of Thror's grandson Thorin. Erebor was lost, for a dragon will guard his plunder as long as he lives.
Their erstwhile ally, the elven king Thranduil, declines to help them. Thranduil would not risk the lives of his kin against the wrath of the dragon. No help came from the elves that day, or any day since. Robbed of their homeland, the dwarves of Erebor wandered the wilderness, a once mighty people brought low.
The young dwarf prince took work where he could find it, laboring in the villages of men, but always he remembered the mountain smoke beneath the moon, the trees like torches blazing bright, for he had seen dragon fire in the sky, and his city turned to ash, and he never forgave, and he never forgot.
At this point Bilbo, having filled in the history leading up to his own appearance in the narrative, decides to tell his nephew Frodo the whole story of his adventure 60 years earlier. One morning in the Shire, a much younger Bilbo sits smoking outside his front door when along comes a tallish fellow. Not a hobbit, he wears a pointed hat and grey cloak.
He's the wizard Gandalf the Grey, and he's looking to enlist the last member of an expedition ready to head off on a quest. Bilbo wants no part of any adventure, but Gandalf has other ideas. Bilbo makes haste to his abode, closing the door. Before Gandalf leaves, he etches an iridescent mark on Bilbo's door, with his walking staff.
As Bilbo sits down to eat the next evening, he's interrupted by a visitor, an imposing dwarf called Dwalin who acts as though he's expected. He wolfs down Bilbo's supper before more dwarves arrive -- Balin, Bifur, Bofur, Bombur, Fili, Kili, Oin, Gloin, Nori, Dori, and Ori -- as well as Gandalf.
They carry all the food out of the pantry, rearrange the furniture, and sing a silly song to tease poor Bilbo. Eventually Thorin Oakenshield arrives and settle down to the business they came to discuss: their quest. Thorin informs them the dwarves of the Iron Hills will not come. Gandalf reveals a map, far to the East, over ranges and rivers, beyond woodlands and wastelands, lies a single solitary peak, The Lonely Mountain.
Ravens have been seen flying back to the mountain as it was foretold: When the birds of yore return to Erebor, the reign of the beast will end. The task would be difficult enough with an army behind them. But they number just thirteen, and not thirteen of the best, nor brightest. They take some solace that they have a wizard.
Rumours have begun to spread. The dragon Smaug has not been seen for 60 years. Eyes look east to the Mountain, assessing, wondering, weighing the risk. Perhaps the vast wealth of their people now lies unprotected. But, the front gate is sealed. There is no way into the mountain. However, Gandalf hands a key to Thorin who instantly recognizes it.
The key was given to Gandalf by Thorin's father, Thrain, for safekeeping. Runes on the map speak of a hidden passage to the lower halls. The answer lies hidden somewhere in the map and Gandalf not have the skill to find it. But there are others in Middle-earth who can. The task he has in mind will require a great deal of stealth, and no small amount of courage.
They wish to hire a 14th member, a burglar -- and Gandalf assures them that Bilbo is a first-rate burglar, or will be when the time comes. Gandalf also says that Bilbo will present a slight advantage to the company when infiltrating Smaug's lair; Smaug is not familiar with the scent of a hobbit and Bilbo will be less detectable to the dragon.
Their contract offers Bilbo a 1/14th share of any profits. After fainting, he refuses the offer. When Bilbo wakes up in the morning the dwarves have all gone, but Thorin has signed the contract. At first he's pleased they are gone. Then he dwells on passing on the adventure, a moment later, he's racing down the road, signed contract in hand.
Bilbo catches up with them on the road and is given a pony to ride. His adventure has begun, although he's still set in his comfortable ways, and complains about the pony rub causing him a skin sore, and even trying to return to his hole in the ground. Gandalf lectures him that his home is now behind him, the world is ahead.
One evening they stop to make camp and Balin tells them of the events after the dragon took the Lonely Mountain. King Thror tried to reclaim the ancient dwarf kingdom of Moria. But their enemy had got there first. Moria had been taken by legions of Orcs lead by the most vile of all their race: Azog, the Defiler.
The giant Gundabad Orc had sworn to wipe out the line of Durin. He began by beheading the King. Thrain, Thorin’s father, was driven mad by grief. He went missing, taken prisoner or killed, they did not know. They were leaderless. Defeat and death were upon them. That is when they saw a young dwarf prince facing down the Pale Orc.
He stood alone against this terrible foe, his armor rent…wielding nothing but an oaken branch as a shield. He disables Azog by severing his arm, leaving him to be pulled away kicking and screaming by some retreating Orc soldiers. Azog, the Defiler, learned that day that the line of Durin would not be so easily broken.
Their forces rallied and drove the orcs back. Their enemy had been defeated. But there was no feast, no song, that night, for their dead were beyond the count of grief. Only a few had survived. Thorin is left in charge of what is left of his grandfather's empire. With nowhere to go, the dwarves scatter to make their way in the world as miners, smiths, and toymakers.
Thorin and company travel east for some days until one evening they break for camp, Fili and Kili are given the task to watch over the ponies. Some time later, Bilbo carries food to the two dwarves on watch and they are puzzled over the disappearance of two of their ponies, Daisy and Bungo. Bilbo, Fili, and Kili figure their 'official burglar' might like to look into it.
They notice something big and possibly quite dangerous has uprooted nearby trees. They see firelight in the distance, that's when they see three large Mountain Trolls, who have now taken two other ponies, Myrtle and Minty. Bilbo is pushed forward to rescue the ponies being kept in a corral, with the promise they have his back.
He sneaks in but is captured by the three trolls, Tom, Bert, and William. They have never seen a Hobbit before. They size up Bilbo as more of a snack than a meal. As they try to snatch him, the dwarves attack the trolls. During the frenzy, Bilbo has freed the ponies, but a troll grabs him.
The dwarves are forced to surrender when the trolls threaten to rip Bilbo apart. Half the company are tied to a large rotating spit over the troll's fire, the other half are trapped in large sacks. The trolls bicker over whether they should be cooked or just squash them into jelly.
Tom reminds them they don't have much time, dawn is coming soon, and he doesn't fancy being turned into stone. Bilbo manages to stall for time by telling the trolls the dwarves are infected. Suddenly Gandalf appears, splits a boulder with his staff and the sunlight turns the trolls to stone.