But Gollum, dancing like a mad thing, held aloft the ring, a finger still thrust within its circle.
“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. Even the smallest person can change the course of the future.
Here Bilbo's long-ago kindness in sparing Gollum's life was rewarded, for Gollum then teetered on the edge of the great pit, lost his balance and fell in, taking the Ring and finger with him along with a final cry of "Precious!". The ring was burned in the molten magma with Gollum dying with it as well.