Stubborn and determined detective Valeria Ferro endeavors to solve the challenging puzzle behind crimes motivated by jealousy, vendettas and repressed anger to seek the truth and justice. All as she struggles with her own demons and the phantoms of her past that come back to life when her mother is released from jail after serving a seventeen-year prison sentence.

The story is one of an architect that has lost his inspiration and goes looking for those motivations that pushed him as a youngster to take up the profession. Inspiring him was the baroque movement and all of its artifices: the Guarini in Turin and the Borromini in Rome. The film’s central story ends up being the love story that develops between architecture, artistic inspiration and feelings.

Prime numbers are divisible only by one and themselves. These numbers are solitary and incomprehensible to others. Alice and Mattia are both "prime", both haunted by the tragedies that have marked them in childhood: a skiing accident for Alice which has caused a defect in her leg, and the loss of his twin sister for Matthew.