- Mar 4, 2020
..when Gollum bites the ring and takes it into the fire that act of mercy ultimately saves Frodo and middle earth.
Yup that's it, Frodo was finally overcome by the power of the Ring and couldn't throw it into the volcano to destroy it, but Gollum bites off his finger with the Ring on it then accidentally topples into the volcano, inadvertently destroying it-
Return of the King Book VI ch 3
Then Frodo stirred and spoke with a clear voice, indeed with a voice clearer and more powerful than Sam had ever heard him use, and it rose above the throb and turmoil of Mount Doom, ringing in the roof and walls.
'I have come,' he said. 'But I do not choose now to do what I came to do. I will not do this deed. The Ring is mine!' And suddenly, as he set it on his finger, he vanished from Sam's sight. Sam gasped, but he had no chance to cry out, for at that moment many things happened.
Something struck Sam violently in the back, his legs were knocked from under him and he was flung aside, striking his head against the stony floor, as a dark shape sprang over him. He lay still and for a moment all went black.
Sam got up. He was dazed, and blood streaming from his head dripped in his eyes. He groped forward, and then he saw a strange and terrible thing. Gollum on the edge of the abyss was fighting like a mad thing with an unseen foe. To and fro he swayed, now so near the brink that almost he tumbled in, now dragging back, falling to the ground, rising, and falling again. And all the while he hissed but spoke no words.
The fires below awoke in anger, the red light blazed, and all the cavern was filled with a great glare and heat. Suddenly Sam saw Gollum's long hands draw upwards to his mouth; his white fangs gleamed, and then snapped as they bit. Frodo gave a cry, and there he was, fallen upon his knees at the chasm's edge. But Gollum, dancing like a mad thing, held aloft the ring, a finger still thrust within its circle. It shone now as if verily it was wrought of living fire.
'Precious, precious, precious!' Gollum cried. 'My Precious! O my Precious!' And with that, even as his eyes were lifted up to gloat on his prize, he stepped too far, toppled, wavered for a moment on the brink, and then with a shriek he fell. Out of the depths came his last wail "Precious!", and he was gone.
...[Later Frodo said to Sam]- "Do you remember Gandalf's words: 'Even Gollum may have something yet to do?'
But for him, Sam, I could not have destroyed the Ring. The Quest would have been in vain, even at the bitter end. So let us forgive him! For the Quest is achieved, and now all is over. I am glad you are here with me. Here at the end of all things, Sam.'