Act IV: Walkthrough

The Infernal Gate from Mephisto’s area brings you to The Pandemonium Fortress in Act IV. This is a relatively short act, although it does take some time to clear mobs while traveling from one area to the next. Notable rewards at a glance are:

  • Q1: The Fallen Angel – rewards you with 2 skill points
  • Q2: The Hellforge – drops various gems plus a rune (note – best to complete this alone with no party/group)
Q1: The Fallen Angel

Speak to Tyrael to give you this first quest in The Pandemonium Fortress. The objective is to seek out and kill Izual.

  • Quest Giver: Tyrael in the Pandemonium Fortress
  • Travel: Outer Steppes > Plains of Despair
  • Objective: Kill Izual and speak to his spirit
  • Reward: 2 skill points


Seek out and kill Izual, found in the Plains of Despair. After you kill him, his spirit version appears. Speak to his spirit and then return to Tyrael back in town.

Q2: The Hellforge

Deckard Cain will give you the second quest. He instructs you to take Mephisto’s Soulstone (the item you looted in Act III) and destroy it at the Hellforge using a Hellforge Hammer.

  • Quest Giver: Deckard Cain in the Pandemonium Fortress
  • Travel: Outer Steppes > Plains of Despair > City of the Damned > River of Flame
  • Waypoints to Acquire: City of the Damned, River of Flame
  • Objective: Kill Hephasto, loot his Hellforge Hammer, and use it to destroy Mephisto’s Soulstone at the Hellforge
  • Reward: 4 various gems plus a rune drop on the floor near the Hellforge to loot

It’s advisable to do this quest solo (meaning no party/group in game). Most players will skip this quest if there are other players in game. You’ll see why further below.


If you previously dropped a town portal where you killed Izual, you can take it back and continue on from there to save you part of a trip.

The Hellforge will be marked on your map once you get closer to it. A unique mob named Hephasto guards the Hellforge. You will have to kill him and loot his Hellforge Hammer.

Equip the Hellforge Hammer, and use it to destroy Mephisto’s Soulstone. This will complete Q2 and also reward you with various gems dropping on the floor around the Hellforge.

Hellforge Rewards (and Tips)

Players generally do Q2 solo in an empty game to ensure they get the full set of gem rewards. The problem with completing this quest with other players in game is that only one set will drop regardless of number of players.

  • 4 random gems – 1 normal, 2 flawless and 1 perfect
  • 1 random rune – range of rune types depends on game mode
Q3: Terror’s End

Unlike Acts II and III, there is no tedious, multi-component quest required to go kill Diablo. Tyrael will instruct you for Q3 to go kill Diablo in the Chaos Sanctuary.

  • Quest Giver: Tyrael in the Pandemonium Fortress
  • Travel: River of Flame (WP) > Chaos Sanctuary
  • Objective: Open the 5 seals, release Diablo, and kill him


Traveling to the Chaos Sanctuary is pretty straightforward. It will always require you to travel East on the map. Once inside the Chaos Sanctuary, you will need to open the 5 seals that are found in three points of the room. There will be two pairs of seals in the northwest and southeast corners. A single seal is found in the northeast corner.

Each seal you click will open it and spawn a set of monsters (including one unique). It’s wise to open each seal after defeating the set of mobs (or else you may overrun yourself).

Once the fifth seal is opened, Diablo will be “released” and spawn in the middle of the room. Defeat him and return back to the Pandemonium Fortress. Speak with Deckard Cain and Tyrael in town. The quest will complete and a portal to Act V, Harrogath, will appear nearby.

Take the Portal in The Pandemonium Fortress to Act V: Harrogath

You can also speak to Tyrael to be taken to Act V, Harrogath, at any time after this point.