He struggles to climb down the rope and Sawyer offers to lower him, but Locke says, "Where would be the fun in that?" And he breaks out his trademark, batshit-insane-but-truly-happy grin. Juliet offers him her thanks for trying to do whatever it is he's trying to do, and he tells her she's welcome. It's a nice, honest moment between these two characters who have had so few honest moments, and who have seldom received much appreciation for the things they've done, even those things which went or meant well. Locke grabs hold of the rope, and I've got to say his arms are nothing to sneer at, either. He swings there for a moment, then begins his descent. Before he disappears, another flash begins. Miles gets to say, "Uh-oh," and from Locke's point of view, we see the flash of light seems to have its genesis in the well. We see Sawyer and Jin outside the well, in shaky cam (which gives me such a headache). Sawyer grabs the rope, steadies it, or tries to, and yells for John to hold on. There's more flashing and then John loses his grip on the rope and plummets to the bottom of the (dry) well. He screams in pain. Oh, John!
Above ground, Miles, Juliet, Sawyer, and Jin try to adapt to the latest flash. We see Jin first, but it's Sawyer who breaks my heart. He's holding onto the rope, pulling it and his whole body seems to quiver, but he doesn't open his eyes. Finally, Miles breaks the silence. "I think you can let go of that, now." Sawyer looks down to see the rope now comes up out of solid ground, and there's no well to be found. He keeps pulling just the same, because he's Sawyer. Then yells, "No, no, come on, help me," as he tries to dig Locke out. Juliet pretty much says, "Really, dude? C'mon," but a little more gentle-like, because that's what Juliets do best.