"In the city of Green Hills, where mobians lived before. Now it was a ghost town because of the accident caused by Eggman machines, so mobians can turn into 2 mutations. One is a weapon serum and the other is a monster serum to make themselves stronger. But the only side effect is hunger for blood, and only a mobian can do that to make them stronger."

"You were a mobian that survived and didn't take both serums, you were about to get going until you see mobians turn into monsters. You went to the door at the right and then locked it behind."

"Then you make this abandoned place into your own house, you look in the mirror to see yourself."