Embun Sitala Laluna, Tala, was suffering from severe hearing injury. When she was seventeen years old, she made a promise with the other six girls of her age that they will be sisters forever. All of them were often treated badly in the orphanage. They made incisions of Sanskrit Hindi numeric symbols on their wrists to seal their oath for the sisterhood. Seven years later, Fulmala Rosa Merona, the fourth sister, found a mysteriously chopped-off human's left hand, bloody with a scar of an incision that was very familiar to hers, a symbol of number one in Sanskrit Numerical, with a new incision scar that said "Sisters Forever". She also saw that the first sister, Arawinda Biru, was miserably hanged up in her room, facing her, with her left hand gone. Many evidences led to prejudgement that Ara could have possibly killed herself. In fear and confusion, the other six women started to believe that their incision scars had become the symbols of some unexplainable curses. They began to experience incomprehensible weirdness. Tala, the seventh sister, was the only one who didn't believe in the curses. Together with a rookie detective, Damar Irsyad Lazuardi, who later came summoned to investigate the cases, she tried to solve the mysteries.