It's the scene where Andy and Red are outside talking... It's what will become Andy's last night in the prison. There is a static electricity in the air (it's about to thunderstorm and they both know it.) Andy talks about a bunch of stuff like freedom, Mexico and "what it comes down to is get busy living or get busy dying."
Oh yeah he also talks about how he scared his wife away and was incapable of showing her how much he loved her... he sort of tries to justify why he is in prison. Red tells him that this only makes him a bad husband, not a murderer. The scene is just unreal... two men who have been through so much shit ahhhhhhhhh it's mind blowing.