The Nether, also known as Hell is another dimension in The Haunting/Haunted universe with Netherrack as the earth and lava as the dominant liquid of the land. Different creatures live in here, being Zombie Pigmen, Blazes, Ghasts, and Magma Cubes (Wither Skeletons and Skeletons may count). Herobrine also possibly originated from this area before encountering Collin.
After gaining all three of the Sacred Diamonds, Drake and Armen head down through the middle temple in The Three Biomes and found themselves in a cave. They head down, but were separated by a trap. Armen goes in the portal first, then Drake. They appear in an arena filled with monsters and Herobrine himself, as well as dispensers on the walls shooting arrows. They fight Herobrine, killing him multiple times until they find TNT to break out of the arena. They do so and traverse through the Nether, talking about past travelers' stories going through this dimension. After finding Herobrine again, they kill him and pick up his flint and steel. They then head back to the arena (the portal was closed upon their arrival) and reactivate the portal and exit the Nether.
In this episode, Drake and Grayson decide to head this dimension after learning that Armen is still alive and so may Herobrine. They fight their way to the Grand Portal, which, unlike other portals, require a special method (much like a ritual) to open it. They then activate it, Drake using his fire magic and Grayson using his flint and steel. They then enter it.
In this episode, Drake and Grayson traverse through the rough, lava-filled terrain of the Nether, fighting off strange monsters and gathering loot from a trail of chests. Drake does not have any memory of going through the Nether although he had been in there in the past during The Haunting: Second Life.