Every year, for one day, the City is invaded by zombies, monsters and vampires, during Hallowe’en (All Hallows’ Evening), an annual event observed around the world on 31st of October, the night before All Saints’ Day.
There does not seem to be any “normal” people around and this gives a big sense of confusion, in a city that can normally already be a bit unique over weekends. Potentially, everyone can be a halloweener. You don’t need to be part of a special group of people.
During Halloween, for at least one night in a year, anyone can experiment a different identity, moving freely in the street, without being considered a “weirdo” and relating to others in a different way than usual.