Spellplague Caverns

This dungeon was removed from the game with the release of Elemental Evil, and reintroduced to the game with the release of The Cloaked Ascendancy. It is unlocked through the task Unlock Spellplague Caverns in The Cloaked Ascendancy (Campaign). Quote from Fifiville on Reddit:

"They removed Spellplague Caverns from the dungeon list so that quest cannot be completed. However, you can get the Eye Chirurgeon achievement still if you go to The Chasm in the Twisted Fane area...look at the map you'll see a path that goes nowhere, that's where the entrance of the dungeon used to be. The boss will spawn as a random encounter."

Right in the very North of the map, there's a "pincer" shape. Take the small path on the right and follow it round (it'll look like you're going off the map) and the Boss is waiting there. ''In the depths of the Chasm of Neverwinter lies the Spellplague Caverns. Enter, and destroy the foul creature responsible for spreading the contagion.''

Description
Located in The Chasm. Entrance is in the north part of the 3rd zone.

You can queue for this, to run it in a 5 man group, or you may enter manually solo or with any size group you desire.

Quests

 * A quest is available upon completing all of the main The Chasm story quests.
 * Name: The Call of the Chasm.

Bosses of Spellplague Caverns

 * Plague Reaver
 * Try to kill the spawning pits before going on boss.
 * A high DPS team can ignore the spawns and burn the boss.
 * It is possible to re-enter the boss arena provided that the mobs are far enough away from the doorway.


 * Mouth of Madness
 * Tough boss, with high damage AoE.
 * The lasers adds are really annoying too.
 * There is a large clearing in the left corner where the 2nd orb is located, that provides a relatively safe position to pull and fight the boss in.
 * Watch the 2 patrolling groups carefully and time your movement to reach the clearing.


 * A'Drx'l the Aboleth Overseer
 * The key to this fight is the Control Wizard(s). They must toss the adds off of the platform while the other DPSers are killing the boss.
 * The Nothic Mindwarps are particularly dangerous, as they can knock you off the edge. The Aboleth Servitors are rather low threat, even as a large mob.
 * Sometimes the boss launches a ray that make the nearby adds immune to toss:
 * Either fight at the opposite edge of the platform
 * Or, have the player with the bosses aggro face him off in a direction away from the adds
 * Every ~20% of hp of the boss, the edge of the platform where the boss is will crack and fall as the boss retreats. This is instant death for anyone standing on the cracked platform.
 * While the boss is retreated, he will not return until the Aboleth Servitors he had under control are defeated.
 * The last 20% of the boss will be on center platform, and the Aboleth Servitors will permanently be immune to control effects, so the only solid way to win is 1 player kite while the rest quickly DPS down the last of his health.
 * A'Drx'l the Aboleth Overseer has 5,000,000 HP.

Loot
{| class="wikitable" ! Epic Boss !!Guardian Fighter !!Great Weapon Fighter !!Devoted Cleric !!Trickster Rogue !!Control Wizard !!Hunter Ranger !!Misc. Loot !!Seals
 * Plague Reaver || - || ||  || - ||  || || - ||3-4 Seals of the Drake
 * Mouth of Madness || || - || - ||  || - || ||  ||3-4 Seals of The Drake
 * A'Drxl the Aboleth Overseer || - || || - ||  || - || ||   ||3-4 Seals of the Drake
 * Mouth of Madness || || - || - ||  || - || ||  ||3-4 Seals of The Drake
 * A'Drxl the Aboleth Overseer || - || || - ||  || - || ||   ||3-4 Seals of the Drake
 * A'Drxl the Aboleth Overseer || - || || - ||  || - || ||   ||3-4 Seals of the Drake