There is no denying that the moment on Weathertop is a sort of climax in Book I, to be outdone only by the confrontation at the Ford at the very end. But between these two terrible clashes, we find an interminably long passage of barren lands and bleak hillsides, and a journey that lasts no less than 14 days. Though Tolkien manages to give us an account of 2 weeks in less than one chapter, the length of time and the dullness of the journey wear off on the reading. Why must this part of the tale be so lacklustre?
The simple answer might be merely geographical. Weathertop is 14 days out from Rivendell, and Nazgul or no Nazgul, the ground simply has to be traversed. Having previously drawn up his map, Tolkien could not miraculously move hills to make the Hobbits’ journey shorter for either them or the reader. Nor, I suppose, was it unfitting that he should make the plodding as grueling on the reader as it was on the Hobbits.
But stepping outside the map of Middle Earth and into the art of the plot-maker, couldn’t Tolkien have done something to make these 14 days more… well, adventurous?
No and yes. No, in that the point of the boring lands specifically seems to be not to provide us with new adventures, but to chronicle the effects of the old adventure on Frodo. The chapter presents us with a series of days in which Frodo must bear the Morgul knife and gradually succumb to its powers. Perhaps Tolkien thought we needed a relatively quiet time period in order to mark how Frodo’s dreams become darker as his arm grows colder.
Yes, however, in that Tolkien does provide us with some adventure through these boring lands, though not the terrifying and mystical adventure of a battle with Ringwraiths. He takes the occasion, instead, to give us a reminder of a comic adventure that once transpired in the very same lands—an adventure involving Frodo’s own forebear, Bilbo, and a handful of Trolls.
There is no denying that the entire adventure is comic, both in its original form in The Hobbit, when the Trolls argue themselves to death over the manner of cooking and eating the Dwarves, and in its rediscovery by the four Hobbits. Pippin is properly scared by the sight of a Troll in midday, forgetting that the sun turns Trolls to stone; Strider gets a chance to shine as he pokes gentle fun at the Hobbits for forgetting this fact and not seeing the bird’s nest behind the Troll’s ear. Even Sam has his brief hour of genius when he spins a nonsense rhyme out of his head in honor of the occasion. The whole adventure serves as comic relief.
Beyond comic relief, however, the adventure has a heuristic point. In the midst of the boring lands, the Hobbits cannot help stirring up the dust of their own history. They are journeying on a road that at least one Hobbit journeyed before them. The lands of Middle Earth remember what has walked through them before; and, just as Tolkien refuses to move mountains on the map of Middle Earth, he refuses to forget the history that he himself already wrote to cover that map.
The Red Book of Westmarch 