During their journey through the marshes, Gollum experiences a personality split. Remnants of his former self, Sméagol return as he feels kindness and, almost, friendship from Frodo. But his corrupted self remains, and through lust of the Ring, overpowers Sméagol as the dominant personality.
Gollum’s guidance leads Frodo and Sam to the Black Gates of Mordor, which they unfortunately find closed. At this point, Gollum saves the day for another time (though his motives are otherwise). He stops the two hobbits from attempting to enter, where they would have no doubt been captured, and the Ring returned to Sauron.
Gollum then reveals to Frodo and Sam his knowledge of a more secretive entrance to Mordor (a path which both personalities had finally agreed to take long before-hand).
Frodo agrees to take Gollum’s alternate path, but Sam is wary, beginning to trust Gollum less and less. But, nevertheless, Gollum, Frodo and Sam travel south from the Black Gates, through the woods of Ithilien. However, here the hobbits are separated from their guide when they are captured by Faramir’s band of men.
They are reunited when Frodo prevents Faramir from killing Gollum (Gollum was found fishing in the Forbidden Pool). Gollum feels that he has been betrayed by Frodo, when Frodo tricks him into coming out of the pool, where he is immediately captured.
Gollum, hateful of the Men of Gondor because of their distrust for him, is more than happy to leave Faramir’s camp after Faramir gives them leave (and extra provisions). But he is unaware that Faramir has warned Frodo about the pass they intend to take into Mordor, Cirith Ungol – the Spider’s Pass.
The hobbits follow Gollum via the Crossroads to the feet of the Ephel Dúath (Mountains of Shadow). They pass the ominous Minas Morgul on the Dawnless Day, and are forced to hide as an army, lead by the Witch King leaves the city, headed for Gondor.
Gollum at last leads them up the Straight Stair and Winding Stair, and finally into Shelob’s Lair. Several times during this journey, he disappears, presumably to make contact with Shelob (a giant spider). Once they have entered Shelob’s Lair, Gollum abandons the hobbits in the darkness, justifying Sam’s mistrust.
Gollum does not appear again until Sam and Frodo are deep in the Lair. He ambushes Sam, with the intent to kill him, while leaving his “nice master” to Shelob. Unfortunately for Gollum, Sam overpowers him, and he scampers off into the darkness after Shelob has been wounded.
