Locke, Kate, and Jack get their first view of what lies beneath the hatch.
Right after breakfast Jack, Kate, Locke, and Hurley gathered a bunch of supplies and hiked to the hatch. They didn't have enough rope to make a ladder, so they cut down some vines for that purpose. Since one of the visible rungs of the hatch ladder was broken, they decided to anchor their rope ladder to the nearest sturdy tree. They got two long vines, nearly a hundred feet long, and cut off many short pieces for the rungs. Locke appeared to have an uncanny ability to make good knots and tie the rungs at even intervals along the long vines. After a couple hours the ladder was completed and ready to be tested. Locke tied a stone to one end, and lowered it into the hatch to make sure it was long enough.
Turning to Hurley, Locke said, "Now we'll see if this is really 42 feet deep." Locke lowered the rope ladder until he heard the stone hit the bottom, and then marked the ladder at a point where it was level with the hatch opening. He then pulled the ladder up, and using a tape measure he had brought along announced, "See, it's closer to 43 feet."
An ominous thought occurred to Hurley "Could you be more precise?"
"Fine," replied Locke, "it's precisely 42 feet and 8 inches."
"Whoa, dude, 8 is also one of the numbers."
That discovery did not please Locke. Hurley was reverting to being superstitious and obsessed with those numbers.
"What's with those numbers, Hurley?" Kate piped in.
Hurley wasn't ready to tell her or Jack the whole story, so just responded with, "Those numbers were on that French woman's transmission, and they are here on the hatch." Hurley pointed them out. "There's something spooky about that coincidence. You can go down there if you want, but I'm staying up here."
Locke then threw the end of the rope ladder over a nearby tree branch, and tied that end to some roots so that it was ready for a test climb. Three pairs of eyes looked at the fourth.
"All right, guys, I'll test it, as long as I stay above ground," grumbled Hurley. Obviously if the ladder withstood Hurley's weight, anyone else could climb it safely. Hurley took one step up the ladder, and then another. The next thing he knew he was falling a couple feet to the ground, but was agile enough to land on his feet and avoid injury. However, the cause was not the ladder breaking, but rather the branch. The branch missed Hurley, but the far end of it knocked down Jack. Hurley muttered, "See, bad luck happens to anyone near me."
"Jack! Are you all right?" asked Kate.
"Yes, it's just a little scrape and maybe a bruise. I'm fine." Jack got up and walked around with a slight limp to try to convince the others that he was okay. Tofurther convince them of that, he took the end of the ladder with the stone attached, and hurled it himself over another tree branch, thicker than the previous one. He continued, "All right, let's try this again," but this time stepped well away. Hurley's test climb proved to be a success on the second occasion, getting up and down several steps with no more mishaps.
Convinced that the rope ladder was safe, Locke repositioned it, so that the ends of the long vines were tied securely to nearby tree roots, and lowered the other end into the hatch. Before anyone else could react, he started climbing down.
"I should be the next one down," insisted Kate, directed at Jack. "You're too important and injured."
"Let's make sure Locke is okay first, all right?" replied the doctor. "Hey, Locke, you okay?"
"Never better," was the reply from the darkness. "I'm at the bottom, and there are a couple of tunnels here. From what I can tell, they seem very well built."
"I'm coming next!" shouted Kate. She smiled sweetly at Jack. "You and Hurley will hold the ladder steady, won't you?"
"Deal, as long as I make the next trip," answered Jack. He felt that Kate and Locke were too eager to dive into the unknown, and wasn't too uncomfortable letting them precede him. Kate was probably right; if something bad was going to happen down there, it was preferable that it didn't happen to the island's doctor. But his curiosity was overwhelming. He would have to see for himself what had caused such an emotional upheaval in Locke, and soon.
When Kate was safely at the bottom, she and Locke turned on flashlights and proceeded cautiously. The bottom of the hatch was located at a corner, with one tunnel heading north and the other west. The walls of the tunnels were about ten feet apart and remarkably smooth, as if some kind of well-built high precision machine had bored its way through some time ago. The floor was also nice and flat, and there was an occasional drop of water falling from the ceiling, about twelve feet high. The pair walked carefully up the north tunnel. It was rather featureless for a hundred yards, when the path became obstructed by a large number of rocks. There was still a noticeable draft, so there was clearly something continuing on the other side.
Kate and Locke retraced their steps to the bottom of the hatch, and shouted out their findings so far to Jack and Hurley. Then Kate and Locke went down the west corridor. Fifty yards in, they found a heavy metal door set into the north face. Like the exterior of the hatch on the surface, there was no handle or anything to give an indication that it could be opened from the outside. Pressing their ears to it, they could barely hear something, like some kind of machinery, behind the door, but it was far too faint to give them any clue as to what it was. Next, they continued along the corridor, and were surprised to find that it ended at an underground river that flowed from north to south.
Unable to make any more progress for the time being, they returned to the bottom of the hatch. Kate climbed up, and being convinced that it was safe, Jack went down, and got a tour of what had been discovered so far by Locke. In a few minutes they returned, ascended the rope ladder, pulled it up after them, and hid it in some bushes. Then as it was nearing twilight, all four returned to the caves, with much on their minds.