"Il sole buio" is a novel written by Giuseppe Pontiggia. The story follows the life of a man named Carlo, who is a successful architect. However, Carlo's life takes a dark turn when he is diagnosed with a rare form of cancer. As he struggles to come to terms with his illness, Carlo begins to question the meaning of life and the choices he has made. Through his journey, he is forced to confront his fears and reevaluate his priorities. Will Carlo find a way to navigate through the darkness and find a glimmer of hope in the midst of his despair?