This is the quest you need to complete to gain access to Penumbra, unless you are lvl 160+ AND have 15k+ Guardian faction. If you meet these requirements, Ergo will give you the ring and let you pass. Be warned: this quest is a pain in the ass
Items Ergo wants to complete his Cold Fusion Cells:
2 x Palladium Filament
2 x Deuterium Collector
1 x Sunburst CF Electrolyte Base
1 x Calibrated Palladium Alloy Trace Base
Other items needed to finish the quest:
1 x Instructions for Dr. Pons (from Ergo)
1 x The Curse of the Watcher
3 x Assorted Metal Dust
1 x Palladium Alloy Calibration Device
WALKTHROUGH:
1. Visit Ergo and pump him for information
Go to Ergo in Adonis Abyss, he is located at 1879x3811. This is, of course, under water, so you will need your Metawater Repellent Spiritech Suit to reach his cave. Talk to him and get the quest, along with the Instructions for Dr. Pons.
2. Get all the items for Ergo
Palladium Filaments:
These drop off Pothole Eremites at the Pothole Mines. They require tanking and healing unless you are lvl 203+ (at which point they will be grey except the boss).
Enter the abyss at 2320 x 1438 (The Outmost Yard) and locate the mines under-water at 1750x1750 and 1971x1813. The boss Eremite seems to drop it more frequently, but not even he drops it all the time. Remember to get two filaments.
Deuterium Collectors:
These drop from Disgusting Parasites, which you will probably be well familiar with by now. Head to any of the meta-water entrance/exit points (preferably not the one leading into Adonis City from Scheol, since there are lowbies coming through that way).
A team with tank/heal/crowd-control IS needed (Fear works quite well), since they have insane HP regen and spawn two when you kill one. Finally you will spawn a boss parasite, who has higher chance of dropping the Deuterium collectors. Keep this up till you have two collectors. Very annoying part of the quest!
Sunburst CF Electrolyte Base:
These are random loot inside the static dungeon beneath the southern-most Ark (huge ancient spaceship NE in Adonis, same one you visited for the Garden key quest). Loot dead mobs, and look inside chests and other containers. The mobs here are only lvl 120-140ish.
Calibrated Palladium Alloy Trace Base:
This is the tricky bit, and will require some skill (in getting a decent team with you) and patience. The mobs you will need to kill are quite hard, so get a good team with tankage, healing (Doc + one more) and crowd control (Crat is best).
Here is the procedure:
a. Kill the end boss (Lollygagger) in the static dungeon at 2461x1740 (area: "The Depression" - the dungeon entrance is marked "Sprawling Hives"). This will spawn two NPCs called Dr. Pons and Dr. Fleischmann.
b. Deliver the Instructions from Ergo to Dr. Pons, and in return he will give you a Palladium Alloy Calibration Device.
c. Give device you received from Dr. Pons to Dr. Fleischmann. He will instruct you to get him 3 x Assorted Metal Dust.
d. Go back the way you came and hunt for Dusty Golems until you have enough dust. There are 12 Golems to kill, and droprate is about 30%. Fear and charm nanos work on them. Being larger than the other hecklers in the dungeon, they are easy to spot too.
e. Return to Dr. Fleischmann and give him the dust. He will give you the Calibrated Palladium Alloy Trace Base
f. Important: Kill spiders that lurk outside the cave, to get the The Curse of the Watcher. Without this item, you cannot complete the quest. Also drops from Adonis brink mobs, especially named ones.
3. Return to Ergo and defeat the Watcher
Head back to Ergo and give him what he wants, to receive the quest to conquer the Watcher of Adonis. Follow the same procedure as for the previous zone rings; you get a Mark of the Watcher item and a key to the static dungeon in Ergo's cave. Use a key dupe to get the other team members with you.
Before attacking the Watcher you will have to use The Curse of the Watcher on him to gimp his attacks (effect lasts 10 minutes). Warning: Without the curse, he hits like Ian Warr...
Good luck!