Quick flash of Desmond turning the key, and the screen goes white. It's Des, on the ground back on the island, coming to after the hatch blew up. He's naked, dirty, sweaty, and bearded, which is not unlike what my weekends look like.
Desmond goes running through the jungle and finds scattered remnants of the hatch: the stationary bike, the dartboard, the ping-pong table -- and then the crater where Swan station used to be. Right nearby, naturally, is his weathered, folded photograph -- fortunately, it was printed on explosion-proof paper -- of him and Penny. He starts crying about how he wants to go back one more time, and he'll do it right, and he's sorry, and he'll change it.
And we whoosh back to Desmond looking at the photo from earlier in this episode (I wouldn't have minded someone announcing, "earlier tonight, on Lost," like they do for "previously on Lost" scenes) with Claire beside him, and we hear Charlie voiceover: "How'd you know Claire was drowning?" and then Desmond's drunk on the beach, saying he could hear her calling for help, and Charlie asks if he could hear the lightning, and we see the scene of Desmond setting up the lightning rod, keeping the lightning from hitting Claire's tent.
And again, a drunken Desmond gets up to walk away, and Charlie calls him a coward. Desmond jumps him, which I don't mind watching again, and yelling about how Charlie doesn't want to know what happened to Desmond when he turned the key. Hurley manages to finally pull Desmond off Charlie, and Desmond yells, "You can't change it! You can't change it no matter what you try to do. You just can't change it." Hurley makes the little finger-twirling "crazy" gesture, and Charlie says they should get him to his tent.
They lift him up, and Charlie drags him over to a tree by the tent, while Desmond drunkenly calls Charlie a good man and apologizes for trying to strangle him. Charlie says he's sorry for calling Des a coward, but Desmond says he's right. "Desmond," says Charlie, squatting down, "you are going to tell me what happened to you," says Charlie. Hey, now's as good a time as any, right? Desmond says when he turned the key, his life flashed before his eyes. "And then I was back in the jungle and still on this bloody island. But those flashes, Charlie, those flashes -- they didn't stop."
Charlie deduces that Desmond saw a flash of Claire drowning, which is how he knew how to save her. Desmond: "I wasn't saving Claire, Charlie. I was saving you." Whuh? "This morning, you dove in after Claire. You tried to save her but you drowned." Charlie, not currently drowned, is understandably confused. "What are you talking about? I didn't drown."