One night, a blackout occurred when May and Jublek are at their tutoring school in Siam Square. It’s not just the building – it’s a blackout in the entire Siam Square, Bangkok’s most famous nerve center of young people. When the lights came back on, they're reminded of the tale of a girl that mysteriously disappeared in Siam Square many years ago. It is rumoured that her spirit has haunted the place, and every time there's a blackout, she will appear to take someone with her. May, Jublek and their group of friends begin to experience unusual incidents, and the myth of the Siam Square spirit becomes more powerful in their minds. Above that, they have to worry about their entrance exam and romantic conflicts that come between them.