Guido, an acclaimed writer, leads a seemingly perfect life with his wife and daughter, but his restless search for inspiration leads him into the arms of Giulia, a charming and mysterious swim instructor who's hiding a secret.

A chambermaid and a former cop meet at a speed dating event and a romance develops. But during a romantic getaway things suddenly take a turn for the worse when her mysterious past is revealed.

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.

Merano detective Andreas Mitterer already has enough problems – the last thing he needs is the "new partner" his superior, Giuseppe Malatesta, has chosen for him. The latter, however, has only the best of intentions, as Mitterer has been traumatized since the accidental death of his wife three years ago, a fact that hasn't gone unnoticed by the rest of his team: forensic pathologist Eva Rossi, forensic investigator Chiara Felice, and team assistant Giuliana Pucci.