Solo Instance.
The area itself is pretty straight forward.
AREA 1
Find or buy a rope to descend into the crater.
AREA 2
A couple mobs in this area have a primitive rock-breaker, use the rock-breaker on the flat rock at veins of marble to open the geyser. Follow the flow of water to get to the next area.
AREA 3
Push on the colored mushrooms in this area, once you get them all you will receive Boon of the Shrooms that will let you advance to the next area. *Note, I suggest killing all of the agg worms and spores in the area before pushing on the mushrooms. The mushrooms will give you a debuff until you push them all.
AREA 4
Kill stuff, talk to Arne, jump geyser to leave.
Quests and runes
First play through- The ghost of Arne at the end of the run asks you to bring him 3 items: A vial, a knife and boots.
The knife comes from the first area west, west, north from Ketill on a wooden table.
The vial is in area 2, a hidden east exit north, east, down, east from "Veins of Marble" where the flat rock that you break with the the primitive rock-breaker.
The boots are in area 4, in a Pterodactyl's nest a couple east from the Maelstrom.
Once you give the three items to Arne he will tell you about the runes that you can activate in future runs of JCE.
URNS
You can buy urns from the shopkeeper in the first area. Kill the three ghosts while an urn is in your inventory to capture the ghost. Give the urns back to the shopkeeper to receive (limited) explorer's climbing gloves. *Note, you can run back to area 1 to turn in the urns.
RUNES
There are 7 runes, activate two runes to get the desired reward.
Rune Combinations- Some of these may be wrong
1 + 2 buff
1 + 3 buff
1 + 4 nothing
1 + 5 nothing
1 + 6 nothing
1 + 7 nothing
2 + 1 treasure chest
2 + 3 nothing
2 + 4 bless
2 + 5 nothing
2 + 6 xp
2 + 7 nothing
3 + 1 nothing
3 + 2 nothing
3 + 4 nothing
3 + 5 monster, two west of rune 1
3 + 6 vengeance
3 + 7 nothing
4 + 1 nothing
4 + 2 monster in underground ocean (down from last ghost)
4 + 3 nothing
4 + 5 treasure chest
4 + 6 RoF
4 + 7 nothing
5 + 1 nothing
5 + 2 xp
5 + 3 nothing
5 + 4 treasure chest
5 + 6 teleport to rune 1
5 + 7 nothing
6 + 1 monster in the underground ocean (1 w of Maelstrom, named Ptero with ptero egg drop chance)
6 + 2 nothing
6 + 3 greater tform
6 + 4 nothing
6 + 5 teleport to rune 1
6 + 7 nothing
7 + 1 ancient green seeds
7 + 2 nothing
7 + 3 ancient green seeds
7 + 4 nothing
7 + 5 nothing
7 + 6 nothing