The Dawn Of Sin by Valentino Grassetti

A psychological thriller where a girl falls in love with an invisible entity that she can only perceive thanks to her brother, a boy with paranoid schizophrenia.

Daisy, sixteen, is determined to pursue her dream of becoming a singer. After an audition she is chosen to participate in a talent show. During the show the judges begin to dig into her past by asking her uncomfortable, often cruel, questions and all in the name of the share. While she confesses in tears that she had a childhood marked by her father's suicide, an accident occurs that causes the violent death of one of the judges. Adriano, Daisy's brother with schizophrenia, knows that this is no accident. Someone, or something, is creeping into the girl's life: an evil and murderous entity that only he can perceive. Meanwhile Guido, a young and shy journalist in love with Daisy, thanks to the accidental discovery of a seventeenth-century manuscript, begins to investigate the life of Pardo Melchiorri, a crippled painter convicted of heresy by the Holy Inquisition. The investigation will lead Guido inside the walls of a Benedictine monastery, where he will discover that Daisy's fate is linked to that of the painter who died four centuries earlier ...