The Lost is a small area that can be found in the Nightmare. It appears to be somewhere in the empty abyssal darknesses and emptinesses of the Nightmare, with each area of The Lost being split up into small fragments that can only be accessed after entering Guttermouth Cells (unlocking the cells with a Guttermouth Key) or accessing the Hidden Key Door in The Grand Hall.
As the players explore the surroundings, they will notice several torches coming out of the pitch-black floors and ceilings of The Lost. They will also notice a large castle-like wall at the end of The Lost, serving as a way to get out of The Lost.
There are four different instances that the players will be taken to, with more details seen in the article, Guttermouth Rewards. All four instances share the same exact environment that players must navigate and survive as they fight against certain monsters of the Guttermouth Cell challenges.
- "Cell 1" - Two Red Wolves & Industry Giant
- "Cell 2" - Two (The Crickets) & Nightmare Lantern
- "Cell 3" - Two Two-Eyed Monstrosities & Guttermouth Effigy
- "The Lost's Boss Fight" - The Lost & Phantoms
- Similar to the Pitfall, both map areas takes place somewhere in the Nightmare's abysses of emptiness.
- The Lost is one of the most dangerous areas to explore and perform activities in, as many monsters can easily kill the players if they are not prepared for the imminent threats they will face in the challenges.