He struggled. He tried. The bravest, best hobbit had come all this way and made so many sacrifices.
Just let it go, Sam pleaded. But he can’t. The Ring has taken hold. No, Sam. The Ring is mine.
At that moment, even as we mourn with Sam for his friend, we know that what flashes in those eyes no longer wants deliverance. It is horrible as Anakin turning to the Dark Side, Obi Wan powerless to stop his friend’s self-destruction. Worse, in Frodo’s case, because he can’t even claim reason and love to be his downfall. It is a gut-like, hungry evil, and has consumed all the goodness that tried so hard to fight.