Kate's determined rescue attempt leads to an encounter with the monster and grave consequences for Walt.
When the monsoons finally ended, there was a flurry of activity around the caves. Everyone was overly anxious to get back outside and do anything to get rid of the claustrophobic feeling that had become pervasive. Sawyer had recovered enough to be up and about almost like normal, though he still had rather limited use of his left arm. The infection had been eradicated thanks to the penicillin concoction and the enforced rest. Locke's legs had mended to the point where he could get around on crutches that he made himself. Needing assistance from Hurley just one last time, Locke was wheeled into the woods far enough for him to select some suitable branches, and then rest was left to his fine woodworking ability. Making crutches was simple compared to making Claire's cradle.
Meanwhile, Michael had immediately sped to his canoe, soon followed by Jin and Sun, but was profoundly disappointed to find it damaged by fallen trees. It wasn't the greatest of shocks, but a bitter disappointment nevertheless. The Korean couple tried to console the anguished father, but the gesture seemed irrelevant. They all knew that they had to repair the vessel as quickly as possible, and set to work removing the fallen trees. They assessed the damage and determined how to proceed. More logs would have to be tied into place to stabilize those that were already there, and some parts would probably have to be replaced.
When things were settled down and under control, Kate and Jack made a surreptitious visit to the hatch. As they somewhat expected, Danielle was there waiting for them. She had brought along a pair of rifles, half a dozen grenades, and a kilogram of plastic explosives. The thought that she had some chance of finding her long lost daughter had changed her, and she was now very cooperative, but still would not let her guard down for a second. The three of them put the rope ladder in place, and descended into the hatch. The hatch itself was not noticeably affected by the monsoons. They made their way down the main corridor, looked at the rockslide that had nearly claimed the life of Locke, and turned left, going to that solid metal door. There was still a muffled mechanical noise coming from somewhere behind it.
Jack still wasn't sure this was the best way to proceed, but the women were determined. There was no hint that the Others had ever been in this area. Danielle rigged the plastic explosives along the edges of the door, inserted a wire for a fuse, told Jack and Kate to go back to the intersection with the main hatch corridor, and lit the end of the fuse. She quickly strode back to where Jack and Kate were, and they all stood behind the corner, waiting. Within half a minute there was a loud boom. The trio cautiously returned to the door, and found it swinging limply from one side. It still took some effort to push that door open wide enough to permit passage, but they succeeded without too much trouble.
Inside the room was a large amount of mysterious machinery, much of it resembling mainframe computers. Myriad rows of blinking lights adorned the machines, but their meanings were completely undecipherable to the small group. They did find one more door, at the opposite end of the room. Louder noises came from behind that one. Still determined to prove herself worthy in the eyes of her island companions, Kate strode to that door, and turned an ordinary handle.
"Careful, Kate," cautioned Jack. "We should try opening that from farther away, in case there's something nasty right behind there."
But Kate was too headstrong to listen. She pulled open the door, and gasped at what she saw. A large robot-looking device occupied the center of the room. It sported numerous knobs and lights, -- and tentacles. At the top of the mechanical creature was a round part, made up to look like a head with a pair of visual sensors. At the bottom of the device, a set of sharp teeth gnashed up and down, as if it were an animal that would chew up anything that got too close or in its way.
The head, if that's what it was, turned toward the intruder, and immediately directed a tentacle in that direction. Kate turned around and ran back from the door, but the tentacle grabbed her around the ankle, causing her to trip. She fell forward, and felt herself being pulled backward by the automatic guard. Danielle reacted more quickly than Jack, and leaped toward Kate, grabbing one of her hands. But the robotic sentry easily pulled both women toward it. Kate had been pulled mostly through the door, when in a last-ditch effort grabbed the bottom of the doorframe with her free hand. This caused the sliding along the floor to stop, but she wouldn't be able to hold on for long.
"Throw the grenade, Jack!" she screamed.
Jack, who had been mesmerized by the spectacle, belatedly sprang into action. He pulled the pin off one grenade, and hurled it into the center of the room. But in his haste he overshot the target, sending the grenade to the far corner. He quickly got another grenade, and this time took better aim, tossing the explosive right at the base of the mechanical monster. He then rushed forward and grabbed Kate's arm, and held his breath.
The two grenades went off almost simultaneously. The tentacle around Kate's ankle released its grip, and Jack and Danielle pulled Kate out of the robot room amid a shower of flaming debris, some of which hit Kate. Then Jack and Danielle helped Kate back through the first room they had passed through, and slammed the heavy metal door back shut. The three of them were quite shaken by the experience, and were out of breath. Very disappointed in the outcome of this rescue attempt, there was nothing left to do but return to caves and take care of Kate's injuries. They include some fairly serious burns to go along with several minor cuts and bruises, though none of that was life threatening. However, that would prove not to be the case for the subject of the rescue attempt. The trio of would-be rescuers didn't have the slightest clue as to how their actions had affected Walt.
At the moment of the explosion, Walt was at the end of the twenty-first corridor to the right, or west, side of the main southern corridor. As he heard the tremendous boom, a large section of the mine wall gave way. The explosion had caused the banks of the underground stream to break apart and burst through the end of that tunnel, and torrents of dirt, water, and mud descended upon the corridor. Part of the ceiling also gave way, showering the corridor with more water and damp soil. Walt started to run toward Alex, who was at the intersection of this corridor with the main one, but in seconds the debris was too thick and deep to move through. With his hands over his head, the frightened Walt felt the soft mud rising up against his legs. In an effort to avoid suffocation for as long as possible, he stood straight up, shielding his head with his hands. As the muck rose over his stomach he took a gigantic breath while he could, filling his lungs to the last cubic millimeter. The mud continued inexorably to rise, and Walt swung his elbows in front of his face to create an air pocket. The terrified boy was helpless to prevent the avalanche of wet soil from covering his head and arms. Then he could feel the landslide stop, right after the mud covered his hands, burying him completely.