Day of the Dead

You wake up in a hotel room in a Mexican town not knowing how you got there, you were woken by the loud music and celebrations taking part outside. As you look outside the window you recognise that people are celebrating the day of the dead and remember that it is that time of year and you won a lottery prize that sent you on a free holiday here. However you notice something.... either some of those people have super realistic costumes or they really are undead celebrating with the living.