Superintendent Teresa Battaglia, expert criminal profiler with four decades of experience on the Italian police force, returns for a chilling cold case. A decades-old murder investigation has landed on Superintendent Teresa Battaglia’s desk. DNA analysis has revealed that a painting from the final days of World War II contains matter from a human heart. Teresa is able to trace the evidence to Val Resia, one of Italy’s most isolated, untouched regions. When Teresa’s investigation hits too close to the truth, a second human heart is hung at the valley’s entrance, a warning not to cross its threshold. Meanwhile, Teresa must not only deal with rapidly progressing physical and cognitive ailments, but also someone she hoped never to see again—a man who is now her supervisor.