If you die in the instance, the revive point is back at the entrance, but if you didn't place a plank across the first gap, and don't have fast enough run speed, you may find it difficult if not impossible to jump the first gap. Try using the horn that sticks out from the side of the cliff if you need to jump.
It pays to have handcrafted Spring-Loaded Gnomish Stilts with you for crossing the gaps. Makes the planks unnecessary.
Pick the quest up by listening to Sarchel the Storyteller at ( -95, -73, -174 ) /waypoint -95, -73, -174. You do not need to listen to the whole story - just the last part - to receive the quest. Sarchel keeps on telling the quest over and over regardless whether any players are nearby or not.
Now either clear or sneak down invisible or stealthed (lighting the fires will remove invisibility and stealth). You need to light 8 fires. Move down a ramp (only possible way down) and:
Move the board at ( 123, -71, -155 ) /waypoint 123, -71, -155 on the first ledge so that you can cross the first gap. Light 2 fires on this second ledge at ( 106, -70, -166 ) /waypoint 106, -70, -166 and ( 91, -69, -168 ) /waypoint 91, -69, -168. You will need to target the wood fuel inside the brazier.
Go down the ramp from ( 94, -71, -180 ) /waypoint 94, -71, -180. There are 2 fires in this chamber at ( 106, -78, -210 ) /waypoint 106, -78, -210 and ( 61, -78, -202 ) /waypoint 61, -78, -202.
Go up the far left tunnel from ( 93, -76, -265 ) /waypoint 93, -76, -265 to reach the Temple chamber. There are 2 fires on the ground in this chamber at ( 41, -66, -278 ) /waypoint 41, -66, -278 and ( 75, -66, -286 ) /waypoint 75, -66, -286.
Get the 4 boxes in this room, plus 2 boxes in the previous room, and stack them all to form a staircase and climb up to the Ark of Harclave. Light the last 2 fires at ( 50, -60, -316 ) /waypoint 50, -60, -316 and ( 60, -60, -317 ) /waypoint 60, -60, -317.
Examine the Ark of Harclave at ( 55, -59, -316 ) /waypoint 55, -59, -316 and you will be granted The Spirit of Harclave; an very strong buff that greatly increases your Max Health and Max Power, increases in-combat regen, and applies a damage shield akin to Brambles. It also decreases your Experience gain by 90%. This will also spawn a group of 6 eternal Tesch Vals around the Ark. If you invis immediatly after examining the Ark you can avoid this fight and head over to Spore King.
NOTE: All mobs just reset. They are now all Heroic. The success zone reuser timer gets set at 8 hours.
The buff will not zone with you when you evac, die or leave the zone.
Next you need to kill a Zygomyd Spore King. Back near the first 2 fires you will find another board at ( 84, -70, -176 ) /waypoint 84, -70, -176. Use both boards to build a bridge and cross over. The Spore King is in the next chamber. It's worth noting that there are multiple heroic encounters in this area. If solo, it pays to pull carefully, even with 'The Spirit of Harclave'. If you can, pull way back, there are multiple wandering yellow groups.
NOTE: If you die in this area, you can still get back across the first gap. Use Sprint and jump at the last moment. It's a bit tricky, you might need a few attempts. If you miss, you'll fall down into an area with some blue gnolls. Stand on the gear looking things and use them to ride back up.
Lastly, Rosch Val Gornas must be defeated ( -100, -63, -94 ) /waypoint -100, -63, -94. You will have to build a "staircase" of crates to reach his ledge, crates can only be placed a couple times. they weaken with each move so build carefully, either before or after he is dead. Once he is dead, click on the throne to complete the quest and be ported back out to Splitpaw Den.