This one?
Back in Osgiliath Frodo hears the calling of the Ring. He walks out from where they are hidden
SAM: What are you doing?
A Nazgul flies over Osgiliath.
SAM: Where are you going?
Frodo stands on top of a wall. As he stand there a Nazgul flies up in front of him. Frodo holds out the Ring to it. Faramir looks up to see the Nazgul close to Frodo. Frodo closes his eyes and starts to put the Ring on. Sam rushes up the steps to him. As the beast reaches out to grab Frodo, Sam grabs him from behind and Faramir fires an arrow into the beast, who flies back screeching. Sam and Frodo tumble down the stairs holding onto each other. They collapse in a heap at the bottom. Frodo rolls Sam underneath him and quickly withdraws Sting, holding it at Sam’s throat.
SAM: It’s me. It’s your Sam. Don’t you know your Sam?
With gradual realisation Frodo sits back dropping Sting on the floor. He slumps back against a wall as Sam sits up
FRODO: I can’t do this, Sam.
SAM: (getting to his feet) I know. It’s all wrong. (he leans against a wall looking out at Osgiliath) By rights, we shouldn’t even be here. But we are. It’s like in the great stories, Mr. Frodo. The ones that really mattered. (he watches a Nazgul fly away) Full of darkness and danger they were. And sometimes you didn’t want to know the end.....because how could the end be happy? How could the world go back
to the way it was...... when so much bad had happened?
Frodo sits panting, tears in his eyes. In Helms Deep the Uurk-hai are running away. Theoden raises his sword in joy.
THEODEN: Victory! We have victory!
SAM VOICEOVER: But in the end, it’s only a passing thing...... this shadow. Even darkness must pass. A new day will come. And when the sun shines, it will shine out the clearer. Those were the stories
that stayed with you......that meant something. Even if you were too small to understand why. But I think, Mr. Frodo, I do understand. I know now.
Gandalf kills another Uruk-hai and smiles. Aragorn pauses and smiles. The flood water continues to flow into the Isengard dungeons and Merry and Pippin look relieved. Saruman backs back into his tower
SAM: Folk in those stories......had lots of chances of turning back, only they didn’t. They kept going......because they were holding on to something.
FRODO: What are we holding on to, Sam?
Sam turns to look at Frodo. Gollum looks on sadly. Sam lifts Frodo to his feet
SAM: That there’s some good in this world, Mr. Frodo. And it’s worth fighting for.
Frodo stares at Sam. Gollum looks solemn and drops his eyes. Faramir appears, walks up to them, and kneels down beside Frodo. Madril and the other soliders appear behind Sam and Frodo
FARAMIR: I think at last we understand one another, Frodo Baggins. (he stands up)
MADRIL: You know the laws of our country, the laws of your father. If you let them go, your life will be forfeit.
Frodo and Sam look worried. Faramir pauses
FARAMIR: Then it is forfeit. Release them.
Frodo looks relieved and Sam brushes a soldier’s hand from his shoulder
That is clearly the movie script. I have doubts that it is in the novel, but am not sure.
In the book it’s a conversation on the stairs of Cirith Ungol. In the book, Frodo is a strong character. In the movie, he is weak. It’s a light hearted section that Jackson turned maudlin. He did the same to the scene where Sam walks into the lake.