The Lord of the Rings by J. R. R. Tolkien is a fantasy trilogy set in Middle-earth. It follows on from Tolkien's prior novel The Hobbit and tells the story of the ring of power.  Each volume of the trilogy is split into two "books"; here follows a summary of the events portrayed in volume one: The Fellowship of the Ring.

Book one introduces the reader to Bilbo Baggins (hero of The Hobbit) and his nephew, Frodo, as they prepare for a party at their home in the Shire.  The wizard Gandalf arrives, and soon the festivities begin. The party culminates in Bilbo's departure from the Shire and Frodo's inheritance of the ring, which Gandalf has started to suspect is the "One Ring" of legend.  Frodo is entrusted with the mission of taking the ring to Rivendell, home of the Half-Elf Elrond.  In this journey he is joined by Sam, Merry and Pippin, other Hobbits of the Shire.  Along the way they are pursued by black riders – wraiths who were once Kings of Men but are now enslaved to the will of the Dark Lord Sauron.  In the town of Bree the Hobbits meet Strider, a Ranger who becomes their protector and guide on the journey.  Frodo is wounded by a black rider at Weathertop but escapes and is delivered, barely alive but still in posession of the ring, to Rivendell.

Book two starts with the Council of Elrond, during which the decision is made to form the Fellowship of the Ring.  Consisting of the four Hobbits, Strider (now revealed as Aragorn), Gandalf, Legolas (of the Elves), Boromir (representing the Men of Gondor) and Gimli (of the Dwarves), this fellowship is tasked with the quest to destroy the Ring of Power.  The fellowship is first turned back from crossing the Misty Mountains by stormy weather at the Redhorn Pass.  Fearing the treachery of the wizard Saruman, Gandalf avoids the only other pass and is forced to lead them through the mines of Moria. When they are attacked by a fearsome Balrog, an ancient and powerful demon, Gandalf bars the bridge to allow the others to escape. However, though he succeeds in stoppping the monster, he falls from the bridge along with it and is lost.  Aragorn, now forced to take over responsibility as leader, guides the fellowship to Lothlórien. This is the woodland home of the Elf Lady Galadriel, who allows them to rest and offers a gift to each to aid them in their task. The fellowship continue their journey by boat, rowing south down the river Anduin.

The Fellowship of the Ring ends with the breaking up of the fellowship – Boromir in a moment of madness tries to take the ring from Frodo, who now realises that he must carry out his task alone. He escapes across the river, accompanied only by Samwise Gamgee, who refuses to abandon his master. The quest to destroy the Ring in the fires of Mount Doom continues in The Two Towers and The Return of the King.