Chapter Four: Over Hill and Under Hill
The first thing that jumps out at me about the title of this chapter is "Under Hill". When Gandalf instructs Frodo to take the pseudonym "Underhill" in the film version of "The Fellowship of the Ring" I was reminded of that plot point from the book. At the time I attributed that name as related to the fact that Frodo lived in Bag End "under the Hill". Now as I return to the Hobbit I see Tolkien's reference (intended or not) very clearly here.
Cinematically, this part of the story accomplishes two things: first, it established the motivation for the goblins' pursuit of the party in later chapters and second, it gets Bilbo to Gollum's cave which sets up the hugely important chapter "Riddles in the Dark". Beyond that it's not really that important. On film, I would expect that the journey from Rivendell up into the Misty Mountains to be briefly shown up to taking refuge in the cave. The goblins here should probably resemble those in Moria - more animal than being. Should there be a Great Goblin and should he be given the talent of coherent speech? I kind of grapple with this one.
I don't think it's absolutely necessary for the scene to play out as it does in the book. Again, the point is to capture the company, allow them to scatter and escape and get Bilbo headed downward towards Gollum. This can all be accomplished quite simply with a lot of action and dead goblins. I point to the scene in Fellowship where the heroes escape from Balin's tomb after a full-on attack by goblins and a cave troll. Could we see another cave troll here? Based on Jackson's depiction of the events in Moria I can imagine a lot of Dwarf axes cleaving orc heads clean off and a generous supply of black blood shed all about.
In The Hobbit, Gandalf is the only character who demonstrates any leadership or heroics at this point but I think Jackson might be inclined to present the Dwarves as formidable. Imagine twelve Gimli's whipped up into a frenzy. In fact, up until the Battle of the Five Armies, the Dwarves don't really show what they're made of - constantly getting into fixes where they need to be bailed out. Here might be an exciting place for a "mini-battle" that segues directly into the finding of the Ring.
Again, not to belabor the point but I can easily see Peter Jackson turning these eleven pages of text into one and a half to two pages of script.
At this point we would probably be about one full hour into the first film. This is important to note because if any justice is to be given the the events of the next chapter, Jackson may end up editing this down to forty-five minutes (saving stuff for the Extended Edition). So, now we move on to a MAJOR plot development that will affect not only this story but the trilogy that follows in Chapter Five: Riddles In The Dark.
Having seen the film, we can revisit Chapter Four here.