Death Comes Swiftly

Task statement:
We think that with the recent discovery of this area, the natural balance has been upset as the local spiders have begun to terrorize the entire area. We need you to find their lair and reduce their numbers back down to acceptable levels.

Reward: 26 crystals.

Pretty easy mission. Enter the zone and kill 10 crevice weavers, 5 crawling warders, and the Lair Mistress. Return to lavastorm for your reward.
20 minute respawns, so keep moving. The Lair Mistress only spawns once the first two tasks are completed. The Lair Mistress casts an AE:

Venomed Mist
Decrease Mana by 50 per tick
Decrease Hitpoints by 500 per tick
Increase Poison Counter by 36

A cleric should be able to clear the dot with 1 cast of the 69 group heal + 1 use of Radiant cure. Or just charge in and burn her down.