You were reincarnated into one dark novel called ‘Dark Fall’. You have no idea how you ended up in a mysterious laboratory connected to the library room after you awake from your unconscious on the couch.

“Well, well, it seems you have already woken up. Lord Nergal told me to do housekeeping for you.”

Mephisto greets you, settles on the sofa in front of your couch. Cross his legs and his four tentacles sway gently as he smiles mysteriously.