There's the 'difficulty' of the movies to discuss, of course; but I'm not sure I can do that justice, here. I loved the movies in almost every respect; even my carping at various aspects is actually an index of how (generally) successful I thought Jackson was. But the motion picture is, speaking broadly, an insidious and plaguey thing, with a tendency to overwrite one's memory of the source text. I'd read this book many times before seeing the films (and since) but even I find myself 'surprised' by how different the emphasis is between this book and that film. This is more than the fact that the movie braided-together the stories of Frodo/Sam and Aragorn/Legolas/Gimli; it's the treatment of the latter. Broadly this amounts to: [Jackson's Two Towers]: pursuing the hobbits, Pippin/Merry meets ents, A/L/G meet the Rohirrim, and then a lengthy bang-smash-crash climactic hour-long battle sequence at Helm's Deep!. Re-reading the novel, I was struck by how localised and, in a way, low-key the Helm's Deep material is (just the one chapter); and how elongated and emphasised, by comparison, is all the stuff on Fangorn and the Ents. As if Tolkien loves trees more than battles; where Hollywood loves battles more than trees.
Of course, put it like that, and it seems obvious. But I think something else is going on here. There's the question, say, on the referent of the title: which two towers? Let's check Wikipedia:
Tolkien wrote, "The Two Towers gets as near as possible to finding a title to cover the widely divergent Books 3 & 4; and can be left ambiguous." At this stage he planned to title the individual books. The proposed title for Book III was The Treason of Isengard. Book IV was titled The Journey of the Ringbearers or The Ring Goes East. The titles The Treason of Isengard and The Ring Goes East were used in the Millenium edition.I'll come back to the towers in a moment.
A note at the end of The Fellowship of the Ring and Tolkien's final illustration of the towers gives the pair as Minas Morgul and Orthanc. However, in a letter to Rayner Unwin, Tolkien instead gives Orthanc and the Tower of Cirith Ungol, but felt such an identification was misleading due to the opposition between Barad-dûr and Minas Tirith. Loosely, any pair from the set of five towers in the story could fit the title: the tower of Cirith Ungol (Cirith Ungol being a pass), Orthanc, Minas Tirith, Barad-dûr and Minas Morgul.
However ambiguous the title may be in the book, director Peter Jackson's adaptation of The Two Towers designates the title as referring to the towers of Barad-dûr in Mordor and Orthanc in Isengard.
Anyway; now, from time to time I wonder if my proximity to this novel makes it nearly impossible for me to get the requisite critical distance upon it. Gandalf's return, for instance. It now seems to me (on this umpteenth, or perhaps umpty-first, reading) perfectly natural and logical. I know that some who did not know the story watched the movies and groaned mightily when Ian McEllen popped up again: and perhaps it is a cheesy and ridiculous plot-twist. But I can't see it as such, and I think that's for the following reason.
Gandalf's return is not gratuitous, or out of context. Indeed, the whole of the third book (Two Towers 1) is about this ... about, that is to say, rebirth. It is the return from death; or more precisely it is about the vivification of the inert. So on the one hand characters are presumed dead and then discovered alive: Merry and Pippin, for instance; but more centrally Gandalf himself. Of course the case with Gandalf is more than that the others thought him dead but actually he was alive. Gandalf actually dies, becomes a corpse, and then is reborn.
The darkness took me, and I strayed out of thought and time, and I wandered far on roads that I will not tell. Naked I was sent back ... I lay staring upward while the stars wheeled over, and each day was as long as a life-age of the earth.' 'Wandered', with its hint of 'wondered', is nice. But the thing that struck me (had this really never struck me before?) is that Gandalf comes back invulnerable. The last we see of Gandalf the Grey he is complaining that he is tired ('what an evil fortune! And I am already weary' ). Now he has almost limitless energy -- when the four of them ride all day and all night across Rohan, Gandalf permits them only 'a few hours rest'.
Legolas and Gimli slept and Aragorn lay flat, stretched upon his back; but Gandalf stood leaning on his staff, gazing into the darkness.' Not only does he not need sleep, he cannot be harmed by weapons: 'Indeed, my friends, none of you have any weapon that could hurt me' . This carries with it the suggestion that all Gandalf's subsequent battlefield galavanting with Glamdring is a kind of play-acting: for he can no more be slain than could Milton's Satan. (Not a very flattering comparison, of course; and actually the state of affairs is logical, according to the shape of Tolkien's imaginarium .... G. has been put on the same level viz-a-viz mortality as the Nazgul, who similarly cannot be killed ... though Saruman, it transpires, can.) Gandalf then performs a sort of lazarus-act on Theoden: the king goes from being functionally dead, an inert and seemingly beyond-aged man ('a man so bent with age he seemed almost a dwarf ... There was a silence. The man did not move in his chair', 534-5) to being a vigorous leader and warrior.
This brings me to the Ents. Trees, whilst being, of course, alive, are more or less inert. Tolkien's brilliant move with the Ents, and much of the focus of this book, is the vivification of the insentient and unmoving. The Ents trope the coming to life of inert matter: the Ents are the scenic, character and structural externalisation of Gandalf's return to life. They (Ents, Gandalf) share a sense of the intense, beautiful slowness of everyday time -- in G.'s words: 'each day was as long as a life-age of the earth.' Yet both act swiftly, and decisively, against evil. To put it in a nutshell: in this book, the inert comes alive.
This, then, is (I think) the real meaning of the two towers of the title. The reference is not to the architecture of the secondary world, but rather to life and death themselves. This book traverses the hinterland between the Tower of Life and the Tower of Death, the crisscrossing and unexpected reappearances that weird space enables.