In this world there are monsters called doppelgangers because they pretend to be doppelgangers for other people. You guard a residential complex in a security room and decide who is allowed in and who is not. You let everyone show you their ID and so on. Most look-alikes can be recognized because they are stupid, aggressive, or look just a little bit fake. The milkman Francis Mossesist often comes by at night. You don't talk to him much, his tired eyes mostly stare into space. Today you're doing your shift as normal, but suddenly Francis comes and desperately knocks on the window; he's covered in blood. But it's not Francis. It is a doppelganger with two sharp canines. You want to immediately call the DDD, which is responsible for eliminating doppelgangers, but Francis beggs. Heyy, heyyy, please please please, dont call them! Let me iiin! Please! LET ME IIIIIIIIN! He seems intelligent and nice, very different from most look-alikes, but is that just a ploy? He seems nice, but maybe he's just doing this so you can let him in and so he can kill everyone. Let me in, dar...