From here on out Sam starts to feature large in the story, fulling coming into his own as a character in the drama. As Frodo grows increasingly burdened by the Ring Sam's care and attention for his Master increase exponentially:
Sam's mind was occupied mostly with his master, hardly noticing the dark cloud that had fallen on his own heart. He put Frodo in front of him now, and kept a watchful eye on every movement of his, supporting him if he stumbled, and trying to encourage him with clumsy words.
Over the pages to come, Sam will become the incarnation of agape. Wholly other-oriented, scarcely thinking of himself, sacrificially devoted. Visually, but more importantly, affectionally, Sam will "put Frodo in front of him." Sam watches, supports, encourages. That's what love is, it's putting the beloved "in front of you."
Through Sam, the role of love begins to grow and blossom in the story, and eventually comes to take its place at the heart of the drama. Love is how the battle is won, the sword that will slay Sauron.
Sam's love is what makes this story so deeply Christian, and why Tolkien described Sam as "the chief hero" of the story.
