In a hole in the mountain there lived a Gollum.
Not a warm, comfortable, well-furnished hole such as Bilbo was accustomed to, but a dark, damp, forsaken hole which even the goblins avoided if at all possible. But is suited Gollum.
The chapter in which Bilbo encounters Gollum is an important turning point in the story. Up to now, Bilbo has felt like -- and has been -- a piece of useless luggage in the dwarves' expedition. His single attempt at burglary at the Troll's camp went horribly wrong and nearly ended in disaster. But here he has the opportunity to be bold and to escape from a difficult and dangerous situation by using his wits and a fair amount of luck.
His first bit of luck, and perhaps the most important bit of all, comes when he reaches out in the darkness and puts his hand on something round and metal which he absently puts into his pocket without thinking. Then he meets Gollum.
We aren't told Gollum's real name in The Hobbit; he is identified by the "gollum" noise he makes in the back of his throat. All we are told is that he has lived many, many years in the dark bowels of the mountain, subsisting on the blind fish from his subterranean lake and the occasional small goblin he was able to catch unawares. Bilbo is probably the most succulant thing he has seen in ages. But Bilbo is also armed with an elvish dagger, a souvenir of the Troll's hoard, and this gives Gollum some pause.
Apprehensive of Bilbo's blade, Gollum tries to break the ice by suggesting a riddle contest. If Gollum wins, he gets to eat Bilbo; and if Bilbo wins... ah, but we'll get to that.
Riddle games, such as the one Gollum and Bilbo plan, were a common feature of the old Sagas that Tolkien used as inspiration. Tolkien devotes as much attentiond to this duel of wits as some writers give to a sword fight; he gives us not only the riddles, but play-by-play commentary on the strategy of each player; why he chose a specific riddle and how his opponent tried to work out the answer. In doing so, he encourages the reader to play along and match his own wits against Bilbo's and Gollum's.
In the end, Bilbo wins through another bit of luck. As he's wracking his brains trying to think of his next riddle, he puts his hand in his pocket and finds the ring he had picked up before and forgotten about. He mutters, "What have I got in my pocket?" Technically, this is not a riddle, as Tolkien admits; but Gollum accepts it, and failing to answer the question, is bound to his agreement.
And here we come to a point of divergence. As originally written, Gollum agreed to give Bilbo a present, which happened to be this magic ring he owned. But when Gollum couldn't find the ring, Bilbo has him show the way out of the mountain instead.
Later on, when Tolkien began writing his sequel to The Hobbit, and decided to upgrade Gollum's magic ring from a Convenient Plot Device to a Full Throttle MacGuffin of Power, he realized that the story of Bilbo's encounter with Gollum did not really fit this new theme. He made the retcon work to his advantage, though, by saying that the version told in The Hobbit was actually the story Bilbo told the dwarves and that the truth was slightly different. And he cited this untruthfulness on the part of the otherwise honest hobbit as a symptom of the Ring's malign influence.
While working on Lord of the Rings, Tolkien did a re-write for his own amusement of the "Riddles in the Dark" chapter to make it consistent with LOTR. He showed it to his publisher, who revised the next edition to reflect these changes. Then a few years later he was asked to make more revisions to create "Authorized Editions" of Hobbit and LOTR to compete with the pirated version published in the United States.
In both editions, Gollum is pitiable creature, for all his cannibalistic habits, but his character is developed a bit more. In the earlier version, when Gollum says "my precious," he is clearly speaking to himself. In the revision, it's a bit more ambiguous as to whether he's referring to himself, or to his Ring.
Another aspect of Gollum's transformation is that he goes beyond just being a hobbit-sized menace for Bilbo to best. He becomes a twisted reflection of Bilbo. Both are small, hole-dwelling creatures, comfortable in their ordered existence until strangers come to upset things. Both come to possess the Magic Ring. But where Bilbo is friendly and open and even generous to strangers within limits, Gollum is secretive and suspicious. Bilbo, at least at the beginning of his adventure, is plump and complacent; Gollum is thin and driven by hunger. Bilbo uses the Ring to help his friends and to avoid trouble; Gollum uses it for nastier ends.
In Lord of the Rings, Gandalf confirms that Gollum actually is a descendant of one of the early tribes of hobbits, something Bilbo's nephew Frodo finds abhorrent. But in the end, Frodo finds that he and Gollum have more in common than he ever imagined. But that comes much, much later.
Instead of forcing Gollum to led him out of the caverns, in the revision Bilbo follows Gollum, using the magic ring to make himself invisible. As Gollum pauses at the opening to the main passage, Bilbo has the chance to kill him and the simple children's story suddenly gets serious.
Bilbo almost stopped breathing, and went stiff himself. He was desperate. He must get away, out of this horrible darkness, while he had any strength left. He must fight. He must stab the foul thing, put its eyes out, kill it. It meant to kill him. No, not a fair fight. He was invisible now. Gollum had no sword. Gollum had not actually threatened to kill him, or tired to yet. And he was miserable, alone, lost. A sudden understanding a pity mixed with horror, welled up in Bilbo's heart: a glimpse of endless unmarked days without light or hope of betterment, hard stone, cold fish, sneaking and whispering. All these thoughts passed in a flash of a second. He trembled. And then quite suddenly in another flash, as if lifted by a new strength and resolve, he leaped.Bilbo spares Gollum, and later on in LOTR Gandalf regards this act of Bilbo's as the most important thing Bilbo did.
"It was Pity that stayed his hand. Pity, and Mercy not to strike without need... Be sure that he took so little hurt from the evil, and escaped in the end, because he began his ownership of the Ring so. With Pity.For the moment, however, Gollum, does not feel any gratitude for this merciful impulse of Bilbo's; he knows only rage as he realize he has been tricked and that hobbit has made off with his Precious. As Bilbo runs down the passageway he hears Gollum furious cry:
"Thief, thief, thief! Baggins! We hates it, we hates it, we hates it for ever!"NEXT: Reunion with the Dwarves; Party with the Wargs; Dinner with Livestock and the perils of Mirkwood