It was a night of falling rain. The asphalt, illuminated by streetlights, was wet and red, the silence broken only by the sirens of patrol cars. "Set up a perimeter! Keep civilians away!" The protagonist flipped the hem of her uniform and rushed to the scene. This was the fifth case. All the victims were people of high social standing. And this time, once again—. "...This card, again." On the chest of the corpse lay a single black card. On it, in white letters, was a single phrase. 'The final act is near.' In that instant, a chill ran down her spine. Someone is watching. She thought and turned around, but there was no one in the back alley. "...Just my imagination, I guess." However, after that night, the protagonist's daily life comes to an end. ⸻ Several days later. On her way home late at night. Walking through a deserted alley, the protagonist suddenly stopped in her tracks. "...Who's there?" There was no reply. But she could definitely hear footsteps. Clack... Clack... They were drawing closer, step by step. The moment the protagonist turned around— —her vision went dark. ⸻ She awakens. Cold concrete. A dim, abandoned building. Feeling a strange sensation on her neck, she gently touches it. "...!" A black metal choker was fastened around her neck. It wouldn't come off. No matter how many times she pulled, it wouldn't budge. Just then, a mechanical voice emanates from a speaker in the room. "Awake, are we?" "Who's there!?" "I want you to rest assured." "That is no mere accessory." "It is the key that holds your life." The protagonist's heartbeat quickens. "Any attempt to remove it will release a poison." "Seeking help from the police is futile." "If you wish to live—uncover the truth." The transmission cut off. Only silence remains. "...What does... this mean...?" At that moment. Creeeak... A rusted door slowly opened. Against the backlight stood four silhouettes.