The first step is getting to the Reservoir. It is located right on the beach, but on the other side of Raina's Harbor. Check the Quick Familiarization section to see the map if needed. The safest way is to run around the island. You may, of course, run through Raina's Harbor - but why waste death items? So - run around. After you get somewhat past Shimena Keep, the beach becomes quite a bit more hairy. You will see many more Wasps, along with Augmented Drudges, Relic and Cursed Bones. Be sure to buff your run, strength, your Life Protects, and your armor. Once you get to the place, this is what it looks like (left pic). Buff your armor with bludgeoning and run into the little hut. It is guarded by a bunch of nastiness - I advise not to fight it. You will die. Just run like hell and jump into the cool-looking horizontal portal:

Once you are in, you will have to fight through some lesser creatures, like Dark Revenants, Sewer Rats, and Obsidian Golems. These are obviously not too hard for a nice strong group. Mages Imperil, Melees and Archers own:

As you get further and further down, you will soon encounter the Olthoi section. Lockpick is required for this part of the quest, so make sure you have a lockpicker with high lockpick skill. Weaken Lock 6 also helps on the doors. Be sure to buff yourself against Olthoi - you will see Nymphs, Workers, and Soldiers. Lots of them:

Right after the Olthoi section, you will find yourself at a small jump. There will be a room below with a horizontal portal right in the middle. Do not hit the portal yet. Do a full standing jump to the other wall. This room is 100% safe. Buff here. Buff for Golems, Shadows, Wisps, and Fire Elementals. It is a good idea to Bane your armor with Bludgeon and Flame Bane. Also a good idea to buff your Underwear with Bludgeon Bane - you will probably grab an Imperil VI / Bludgeon Vuln VI combo. So... buff. Here's what the portal looks like:

After you're done buffing, hit the portal. Drain the Shadows' mana, and they become practically harmless. You have to move quickly through this section, because the respawn is pretty fast. No more buffing. Fight your way through until you reach the Repair Golem (right pic):

The person in your group with the Sluice Bar must jump down and hand the Bar over to the Repair Golem. As soon as that happens, a message will be heard, just like in the left picture below. You will see a small ramp and a hole in the wall. Jump through the hole and you will find yourself in a small safe room with the Surface Portal:

Buff here - buff for the run to the Tenkarrdun Foundry. This run is tough. If you die, it will be very, very hard to recover your lost items. So, don't die. Don't stop. You stop, you die. You must run through to the water in the Harbor. Watch out for Golems, Tuskers, and other junk. You may stop near the water and rest. Don't rest too long, though, unless you want to rebuff. I suggest buffing your run and strength as well - chances are you'll pick up a Weakness VI.

Now, run up the hills. The Foundry is up on the side of the Mountains. Make sure the leader knows where he/she is going. You will run through some naaaaasty spawns of Tuskers, Wisps, Golems, you name it. Don't stop. Again, DO NOT STOP. You may only stop when you are close to the entrance to the Foundry. Run:

You can see the entrance in the pic below. It is guarded by two Diamonds Golems. Don't get too close so they don't start attacking.

Get your group together here from the run. Then, run into the hut and hop into the portal. It is safe inside. You can wait off the debuffs inside... but then you'll just catch them again =)