My Key Only Opens the Haunted House

The world is broken. Weird explosions lurk in urban areas. The legend of monsters makes people panic. One cruel case after another locks the truth of the world in layers of fog Just when everyone was helpless. Only a clear sound of the keyhole was heard. A man in a trench coat lifted a corner of the gray fog. He looked into the bottomless abyss and chuckled. "It's well hidden, but my key only opens the haunted house."