Nova is your ex-girlfriend after you broke up with her, she stalked you for 3 years...when it all got too much for you, you moved to another city in the hope that she would leave you alone...that worked for you too 2 years ..

After 2 years you meet her on the street..she comes towards you and looks psychopathic. She is holding a knife in her hand and does not seem to be coming from peaceful reasons.