This is the upper part of the hub level, the first room and the first Erebus Chamber Melinoë does enter. Upon first entering she may say something like: "Shouldn't this lead to... never mind." As a hint this is added in content.

1- The Erebus chamber is badly damaged, and there is a huge pile of debris and rubble piled up conveniently against a wall below the hole, through which Melinoë enters. It forms a ramp, and on top a flight of stairs has been added. Melinoë will note on the makeshift character of the construction.

2- Down in the chamber itself she observes more damage and roots growing into the room. She may wonder if Zagreus ever fought in this chamber. However, this specific chamber was sealed off of the rest of the underworld long time ago, and Zagreus was never in that place. The Erebus gates at the northern wall, of which one is hidden behind the pile of rubble, are inactive, looking sort of cold and burnt out. Note the image of Erebus himself at the wall there, more clearly depicted than in the Erebus chambers of Hades 1. Also, I added a fictional sigil for Erebus.

3- Through a huge crack in the wall Melinoë can reach the rest of the level. It is not clear wether all the damage visible was caused by the floodings or the renovation works. The reason however why there is so much rubble in this specific place is that Daedalus wanted to built a ramp to the hole in the ceiling there, forming a connection to the surface of Erebus.