Frodo, Sam, and Gollum reach the Black Gates of mordor, but cannot enter, as they are too heavily guarded. Gollum leads them up through a secret path into Mordor, but, after Sam grows suspicious of his action, tricks Frodo into abandoning him.
The destruction of the ring also caused Sauron to explode, creating a massive earthquake, that eradicated most of the enemy forces at the Pelennor fields. The remainder of the fellowship was thus reunited, and the hobbits returned to the Shire. Frodo wrote about his adventure in the remaining pages of the book about Bilbo's story, but, eventually, set of with the Elves, Gandalf, and Bilbo to the Undying Lands, and left Sam to finish the story.He then leads Frodo into the lair of Shelob, a gigantic spider, in the hopes that, once the spider killed Frodo, he could take the Ring. Sam fended off Shelob, but she still managed to inject him with venom and cocoon him, which put him into a comatose state. Orcs arrived and brought Frodo to their tower, forcing Golum to flee. Sam arrived at the orc's lair, finding most of them dead at their own hands, after arguing over the ring. Sam then freed Frodo, and, together, they finally reach Mount Doom. Frodo was about to destroy the ring, but, realised that he couldn't. The ring's power over him was not too strong. It was at that point when Gollum ambushed them. Gollum took back the ring by biting of Frodo's finger, but overbalanced on the edge of the cliff leading into the volcano's fiery interior, and perished, along with the ring.