en Cuevana 3. Ferdi comes to Istanbul to seek treatment for his mentally disabled sister, Oya. During the treatment process, he works as a singer in a nightclub. When he goes to work, his sister stays home alone. One day, when he returns home, he cannot find his sister. Thinking she is lost, he reports it to the police. Some time later, he receives the news that his sister has been murdered. Ferdi will try to take revenge on his sister's killers.