The protagonist of this book is Frodo, who has been chosen by Bilbo to carry on the responsibility of possessing the Ring. Frodo represents Good in the novel's epic struggle between Good and Evil. Frodo proves himself to be brave and clever, managing to avoid danger and earn the trust of his many friends. In the end, Frodo is nearly controlled by the weight of the Ring. But he resists and emerges heroic. When the novel closes, Frodo accompanies Bilbo into the Grey Havens, leaving his work and legacy to his dear friend Sam.
There are many antagonists in the novel--all agents of Evil led by Sauron and Sarumon. Sauron is a satanic ruler who is consumed by his desire for power. He commands all manner of evil, including the Black Riders and the Nazgul. Sauron is omnipresent especially because of the palantirs, which give him insight, and the Eye, with which he is able to see the goings-on of the Ring bearer.
Sarumon is a fallen wizard who has been corrupted by his own thirst for power. Though he is a villainous force, Sarumon is also a character to be pitied. Many times, Gandalf tries to persuade Sarumon to repent and claim his former position of respect and glory. But the corrupting influence of power is too great for Sarumon. He destroys the Shire and tries to present Frodo from disposing of the Ring.
There are other characters whose actions constitute evil, or the forces that act against Frodo. Some of these characters are temporarily driven to their evil acts, such as Boromir. Some are permanently ruined by their hunger for the ring, but remain characters to be pitied, such as Denethor.
Shelob and the orcs are characters whose grotesque evil only increases anxiety for the protagonist. Shelob and the orcs are pure evil--beings whose sole purpose in life is to cause trouble for the hero. They are onedimensional beings of wickedness.
There are many climaxes in the novel, especially since it is broken into three parts, six books, and multiple chapters. The ebb and flow of dramatic intensity continues to build, however, till the climax of the novel, which occurs when Frodo is ready to toss the Ring into the flames of Mount Orodruin. This has been his objective all along, and the struggles to get to the Crack of Doom have been fierce. Gollum nearly ruins Frodo's objective by biting off the finger that holds the Ring. But Gollum gets too excited and ends up falling into the crack, carrying with him the Ring and thus completing Frodo's mission.
The outcome is still fraught with tension. Though Sauron has been defeated, the Shire is destroyed. Sarumon is still wreaking havoc disguised as Sharkey, and Frodo and his friends are still wounded from battle. The outcome is the gradual recovery of the travelers, the rebuilding of the Shire, the defeat of Sarumon, and the retirement of Frodo. Just as the novel opens with Bilbo passing his legacy down to Frodo, it closes with Frodo doing the same to Sam. The final vision is of the new generation, Sam's daughter, and the hope for the future.