I'm Henry...this is Sam is the nineteenth of thirty-eight Cinematics shown in The Last of Us. It is approximately one minute and forty-five seconds in length. Below is the complete transcription for this cutscene's spoken dialogue.
Note that the dialogue is copied from the subtitles.
Ellie: "Oh shit!" [Jumps in through window and swings her switchblade.]
Henry: [Throws back Ellie with his arm, getting cut in the process.] "The fuck?" [Henry stares at Ellie, slackening his grip on Joel.]
[Joel slams Henry's head on the wall behind them. Reaching back, he grabs Henry's head and flips him over his back and onto the floor. He delivers heavy blows to Henry's side and face.]
Ellie: [Worried.] "Joel.' [Joel continues to punch Henry. Ellie shouts.] "Joel, stop!" [Joel looks over at Ellie and she points across the room.] "Look."
Sam: [Still aimed.] "Leave him alone."
Joel: [Backs up.] "Easy, son. Just take it easy."
Henry: [Extends arm.] "It's alright. They're not the bad guys. Lower the gun."
[Frightened, Sam hesitantly lowers the handgun. Henry sits up.]
Henry: "Man, you hit hard."
Joel: "Yeah, well, I was trying to kill you."
Henry: [Stands up.] "Yeah, I thought you were one of them too." [Points at Ellie.] "Then I saw you." [Cut to Joel, looking at Ellie. Cut to all.] "In case you ain't noticed, they don't keep kids around." [Pauses.] "Survival of the fittest." [Winces and looks at his arm.]
Sam: [Worried.] "You're bleeding."
Henry: "Ah, it's nothing." [Takes gun from Sam and reaches inside Sam's backpack. To Joel and Ellie.] "I'm Henry. This is Sam." [Pulls out bandage.] "I think I caught your name was Joel?"
Ellie: [Waves.] "Ellie."
Joel: "How many are with you?"
Sam: "They're all dead--"
Henry: "Hey." [Looks at Sam.] "We don't know that." [Looks away and continues bandaging arm. To Joel.] "There were a bunch of us. Someone had the brilliant idea of entering the city. Look for supplies. Those fuckers--they ambushed us. Scattered us. Now it's all about getting out this shithole."
Ellie: "We can help each other."
Joel: [Interrupting] "Ellie."
Ellie: [To Joel.] "Safety in numbers and all that."
Henry: 'She's right." [Shrugs.] "We could help each other. We got a hideout not too far from here. Be safer if we chat there."
Joel: [Pauses.] "Alright, take us there."