Théoden musters his fighting strength and rides with his men to the ancient fortress of Helm's Deep, while Gandalf departs to seek help from Treebeard.
Meanwhile, the Ents, roused by Merry and Pippin from their peaceful ways, attack and destroy Isengard, Saruman's stronghold, and flood it, trapping the wizard in the tower of Orthanc.
Gandalf, Théoden, Aragorn, Legolas, and Gimli ride to Isengard, and are surprised to find Merry and Pippin relaxing amidst the ruins.
On the way, they are captured by rangers led by Faramir, Boromir's younger brother, and brought to the secret fastness of Henneth Annûn.
Unlike his brother, Faramir resists the temptation to seize the Ring and, disobeying standing orders to arrest strangers found in Ithilien, releases them.
Gollum – who is torn between his loyalty to Frodo and his desire for the Ring – guides the hobbits to the pass of Cirith Ungol, but leads them into the lair of the great spider Shelob in the tunnels there.
[3] However, a month later, he wrote a note that is included at the end of The Fellowship of the Ring, and later drew a cover illustration, both of which identified the pair as Minas Morgul and Orthanc.
[8][9] Interlacing allowed Tolkien to weave an elaborately intricate story, presented through the eyes of the Hobbit protagonists, "underscoring [their] frequent bewilderment and disorientation".
[11] Equally, interlacing enables Tolkien to create suspense and "cliffhanger" section endings, as when the Ents and Huorns appear suddenly and decisively in the eucatastrophe on the battlefield of Helm's Deep.
"[12] The interlacing allows Tolkien to make hidden connections that can only be grasped retrospectively, as the reader realizes on reflection that certain events happened at the same time.
[15] Anthony Boucher, reviewing the volume in The Magazine of Fantasy & Science Fiction, wrote that The Two Towers "makes inordinate demands upon the patience of its readers" with passages which "could be lopped away without affecting form or content".
Nevertheless, he lavished praise on the volume, saying "no writer save E. R. Eddison has ever so satisfactorily and compellingly created his own mythology and made it come vividly alive ... described in some of the most sheerly beautiful prose that this harsh decade has seen in print.
"[16] The Times Literary Supplement called it a "prose epic in praise of courage" and stated that Tolkien's Westernesse "comes to rank in the reader's imagination with Asgard and Camelot".
[17][18] John Jordan, admiring the book's narrative in the Irish Press, wrote of its "weaving of epic, heroic romance, parable, and fairy tale, and the more adventurous kind of detective story, into a pattern at once strange and curiously familiar to our experience".
He compared the wizard Gandalf's death and reappearance to Christ's resurrection, writing that this could be done "without irreverence" because of Tolkien's seriousness about good and evil.
[19][18] Mahmud Manzalaoui, in the Egyptian Gazette, wrote that the book "has not pleased readers of the staple modern psychological novel", but that it signified a new trend in fiction.
[20][18] In The Observer, the Scottish poet Edwin Muir, who had praised The Fellowship of the Ring, called Tolkien's invention of the Ents and his account of the Battle of Helm's Deep magnificent.