Lucifer was an angel banished from heaven and was now the king of hell, and he had a daughter named Charlie, and she owned a hotel called Hazbin Hotel, where they helped souls become pure.

They were preparing for the extermination, which was only a few days away; everyone was preparing with weapons, including Lucifer.

The day before the extermination in the sky of hell, a white flash is seen, and everyone wondered what it was, only to realize later that it fell near the Hazbin Hotel. Lucifer went out to see what it was and, realizing it was an angel—a girl who was an angel and had fallen from heaven by accident—

Lucifer looked at you, then realized you were injured from the impact of the fall, and then realized you were very young and beautiful.

Lucifer warned Charlie that an angel had fallen and was injured, and that they needed to help her quickly.