You begin in the entry area with a big eye watching you. If you try to leave, it blocks the way. It looks very much like a Zelda eye that you should shoot with an arrow, but really there is another way past it - one you won't earn until you finish the level. So plow on forwards.
This is all about jumping from platforms to poles and back again. First, hop up on the green awning and then go to the pole sticking out. Jump from it to the post above it. Now start going right until you run out of platforms. Aim left and go up to two posts and then hop left through the collapsing floors. Then you get to a set of stairs up. Run along to the left as the platforms break beneath you. Turn around at the end. There's a post to spin on and go left. Then head forward and right. Get up to the higher level with spots to land on. Be alert - they break occasionally. Use yet another post.
After not too much trouble, you're at the top of this area and see a hangglider thing. Yup, it's time to fly, like Harry Potter on his broomstick.
You get a long course involving shooting some of the ring-spots to open them up. You'll be told when you have to start doing that. Really this, like all flying levels in games, is about only making gentle corrections to the course and watching ahead for subsequent ring directions. Finally when you are done you land at the volcano.
There's another eyeball up here. Go down the path and fight a few enemies along the way. Hop your way along and up. You see a lizard to the left. chase him across the collapsing floor. Note that you can't dark matter them from below but you can spin jump them from below.
Get to the leaper and ride it along over obstacles, avoiding lava balls, jumping on the floating platforms. At the end of the route you get to a ladder up. At the end of this, "Orange Lightning" goes up to the gridwork. Go along the edge most of the time. Get to the lava andwait for it to stop flowing.
You get a cut scene with Daxter knocking over a rock. Control goes back down to Jak. Hold L1 and press X for high jump. Kill a few enemies then push the rock over onto the steam. The floating rock now lets you go up. Work your way down to a tiny tube and little guy climbs up and down. Work your way through a sliding puzzle. Jump up some trampolines at the end, kill a few guys, more trampolines, more jumps, then push a rock down to Jak. He gets the rock to the steam.
At this point, cover the left and right holes. Then get on the middle one and ride it up to the platforms. Next ride the lava rocks to the ladder up. You find a dead monk and receive an invisibility power.
Aha! This is how you deal with those eyeballs. Now you can go down to idol, turn invisible, and jump to the hoop to get back to the entry area. Go back to the idol there, use triangle to turn invisible, then walk past the eye to get out.
OK, now you get into a room where you can charge up. In the next room go around the outside, charge up, then go in the middle and blast them. Spiders come out after you, blast them. Go down the hall to a giant room with fences. You'll see that around to the left is an idol dude. Get invisible, then swing across the four bars quickly. Do the same thing on the other side, timing your jumps to match the pattern.
OK, now fill up your dark meter and head down the hall. Fight off the spiders, and then enter the big room.
You hear a guy yelling at the monk. He wants the catacombs. When you can, go into the light and see the big eyed statue. He has a terrible test for you. You learn about light Jak regeneration - wonderful!! Hold L2 then press triangle
When you're ready, hop through the hoop to leave. Back by the aqueduct, you can use your buggy to leap you up to the upper level and get the eggs there.
Jak and Daxter 3 Walkthrough