The Deep levels are where you will get to the good stuff in Moria. On 2 Deep, you will find an altar that will lead you back to the 4th Level if you decide to clean it. Otherwise, find a small pit blocking the passage, and use the JUMP skill to get across. In the far northeast part of this cave you will find Kiri. If you can, RECRUIT him; in you can't, just leave him. South of Kiri, you will come across two Snagas - really wimpy orcs. Kill them and go west. Here you can kill two Uruks to get Smith's Ring back if you gave it to Drisnak.
When you descend to this level, Gimli will say that you are getting into some heavy orc territory. He is correct (as usual) because you will soon run into two of them. When they are dead, find the stone troll that is guarding a passage. Kill the troll and head to the tombs. Use PERCEPTION and you will notice that a stone slab can be moved. USE the prybar to reveal a passage down. If you have a rope, USE it now; otherwise, use the CLIMB skill to get down. Without a rope it is very difficult to get back up since you need to move in very small increments at the end of the passage; keep trying the CLIMB skill until you can get out. Now that you are down, just where are you? This level (which I will call Durin's Level) leads to Durin's Axe, the main goal of Moria. If you have the gold anvil, chisel, and hammer, continue. If you don't, exit back up out of Durin's Level because you will need these three items. Durin's Level is explained near the end of this section.
This is a fairly large level and you will be fighting many foes, so be sure your stamina is up. To the north of this level is a pool with two bridges leading from the mainland to a small island. Cross either one of them, and find the stairs up. You will have to kill an Olog-Hai before you can continue. After the Olog-Hai is dead, go to the southeast corner, and use the PERCEPTION skill. You will see a small passage leading up. USE the prybar, and then CLIMB up. Go north a bit and you will have to defeat yet another Olog-Hai. After it is dead, the bird will give you the KHAZAD word of power which is used to free Oin and Ori on Level 5. Exit back out, and cross either bridge again. This time across, however, you will have to fight 3 sets of 2 tentacles each, and they are not easy. The exit down is found in the southern region of this level.
This is one of the smaller levels in Moria, and it holds two things of interest. First, you will notice a set of several staircases leading down. Don't take them. You will have to fight two trolls to get to a set of tombs. When you get to the tombs, you can use the prybar to release yet another troll. It seems like it was just a false passage to help decrease your stamina. Second thing on this level, if you enter one of the side rooms, you will be attacked by two Uruks. Kill them, and GET the magic mail and the axe. Walk the center of the room to the hole and use PERCEPTION to find some mithril mail.
After descending to 6 Deep, you will immediately enter a large hall. In the center of the northern part of the hall is a gold throne, but when you approach, you will be attacked by some trolls and orcs. After killing them, I found nothing to gain from the throne, so I suggest hugging the south wall of the hall, and avoiding it altogether. Along the south wall you will notice two small rooms. In the western room you can get back up to level 1 by walking into the west wall. But you can only get back down if you have the star key! The exit from this hall is to the west, cross the bridge, JUMP the chasm, and from here you can north or south. On the north passage you will find a pit. Get close to the pit, and use the CLIMB skill to get down to 7 Deep.